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  • HOw do I limit array to a certain number??

    - by mathew
    I do have an array which queries database..what I need to do is control this array to a certain number say 10. but I dont want to set LIMIT in mysql query I need to leave that as it is... $result = mysql_query("SELECT * FROM query ORDER BY regtime DESC"); while($row = mysql_fetch_array($result)) { echo "<img src='bullet.gif' align='absmiddle' class='col1ab'><a class='col1ab' href=".$row['web']." >www.".$row['web']."</a><br>"; } How do I limit this array to certain limit??

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  • How to remove $ from associate array using Json_decode in php?

    - by Chase
    I am trying to use the youtube API to pulldown some videos for my site. Currently am running this code here: //Youtube Videos Pull Down $youtubeURL = "http://gdata.youtube.com/feeds/api/videos?alt=json&q=cats+cradle+chapel+hill&orderby=published&max-results=10&v=2"; $youtubeSearch = file_get_contents($youtubeURL, true); $youtubeArray = json_decode($youtubeSearch, true); Not having any problems accessing certain elements of the associative array however youtube's api is putting $ in many of its array elements .. such as [media$group] Anytime I try to access an array with one of the $ elements in it, it doesn't work. Suggestions? I have tried preg_replace but can't seem to get my expression right.

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  • How do I add values in an array when there is a null entry?

    - by Angela
    I want to create a real time-series array. Currently, I am using the statistics gem to pull out values for each 'day': define_statistic :sent_count, :count => :all, :group => 'DATE(date_sent)', :filter_on => {:email_id => 'email_id > = ?'}, :order => 'DATE(date_sent) ASC' What this does is create an array where there are values for a date, for example [["12-20-2010",1], ["12-24-2010",3]] But I need it to fill in the null values, so it looks more like: [["12-20-2010",1], ["12-21-2010",0], ["12-22-2010",0], ["12-23-2010",0], ["12-24-2010",3]] Notice how the second example has "0" values for the days that were missing from the first array.

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  • How to Create an Array from a Single Variable and Form Multiple Foreach Loops?

    - by matphoto
    I'm fairly proficient in HTML/CSS, but very new when it comes to the likes of PHP and Javascript. I've jumped headfirst into coding Wordpress shortcodes (basically php functions), and so far, through trial and error and seemingly endless browser refreshes, I've been able to figure everything out. I just hit a huge wall though, hence why I'm here. Basically, I'm trying to give an attribute a list of values like: attr="23, 95, 136, ect" The function then needs to take that attribute variable and create an array with it: $arr = array($attr); To me that seems as if it would work, but the array takes the whole list as one value instead. After doing that I want to create a foreach loop that parses each number from the list, possibly through yet another foreach loop if possible, and returns a section of code for each one, and I'm not quite sure how to pull that off either. Any feedback would be greatly appreciated.

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  • Why does document.QuerySelectorAll return a StaticNodeList rather than a real Array?

    - by Kev
    It bugs me that I can't just do document.QuerySelectorAll(...).map(...) even in Firefox 3.6, and I still can't find an answer, so I thought I'd cross-post on SO the question from this blog: http://blowery.org/2008/08/29/yay-for-queryselectorall-boo-for-staticnodelist/ Does anyone know of a technical reason why you don't get an Array? Or why an SNL doesn't inherit from an Array in such a way that you could use map, concat, etc? (BTW if it's just one function you want, you can do something like NodeList.prototype.map = Array.prototype.map;...but again, why is this functionality (intentionally?) blocked in the first place?)

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  • How can I remove a duplicate object from a MongoDB array?

    - by andrewrk
    My data looks like this: foo_list: [ { id: '98aa4987-d812-4aba-ac20-92d1079f87b2', name: 'Foo 1', slug: 'foo-1' }, { id: '98aa4987-d812-4aba-ac20-92d1079f87b2', name: 'Foo 1', slug: 'foo-1' } { id: '157569ec-abab-4bfb-b732-55e9c8f4a57d', name: 'Foo 3', slug: 'foo-3' } ] Where foo_list is a field in a model called Bar. Notice that the first and second objects in the array are complete duplicates. Aside from the obvious solution of switching to PostgresSQL, what MongoDB query can I run to remove duplicate entries from foo_list? Similar answers that do not quite cut it: http://stackoverflow.com/a/16907596/432 http://stackoverflow.com/a/18804460/432 These questions answer the question if the array had bare strings in it. However in my situation the array is filled with objects. I hope it is clear that I am not interested in a query; I want the duplicates to be gone from the database forever.

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  • How can I send an array of strings from one ASP.NET page to another?

    - by Andrei
    Hello. I now have two asp.net pages. When I click on a link on page A, I open the other one (let's call it page B). When I do this, I want to send some information from Page A to Page B in the form of an array of strings. This array is different depending on what link I follow on Page A. I know I could send this information via the URL with the ?string1=bla1&string2=bla2 etc., but I don't want it that way, as it can get complicated if there are too many strings in the array. I think there is something similar, like a POST in PHP, but how would that be in ASP? Any help would be appreciated. Thanks. Cheers!

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  • How to get two different array checkbox value in Jquery?.

    - by boss
    Hi.. For example i have 5 checkbox, 3 checkbox with name=a[] and 2 checkbox with name=b[], if i checked array a[] 3checkbox iam getting the same value for b[] checkbox even b[] checkbox not checked. please suggest... For ur reference: var selectedAItems = new Array(); $("input[@name='a[]']:checked").each(function() { selectedAItems.push($(this).val()); }); var selectedBItems = new Array(); $("input[@name='b[]']:checked").each(function() { selectedBItems.push($(this).val()); }); alert(selectedAItems); alert(selectedBItems );

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  • Sorting array of 1000 distinct integers in the range [1, 5000], accessing each element at most once

    - by Cronydevil
    Suppose you have an array of 1000 integers. The integers are in random order, but you know each of the integers is between 1 and 5000 (inclusive). In addition, each number appears only once in the array. Assume that you can access each element of the array only once. Describe an algorithm to sort it. How i can sorting? If you used auxiliary storage in your algorithm, can you find an algorithm that remains O(n) space complexity?

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  • How can I initialize a 2d array in Perl?

    - by Mark
    How do I initialize a 2d array in perl? I am trying the following code: 0 use strict; 10 my @frame_events = (((1) x 10), ((1) x 10)); 20 print "$frame_events[1][1]\n"; but it gives the following error: Can't use string ("1") as an ARRAY ref while "strict refs" in use at ./dyn_pf.pl line 20. This syntax only seems to initialize a 1d array as print "$frame_events[1]\n" works. Though perl doesn't give any error during the assignment.

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  • Constant time change first k elements of an array in C++?

    - by Johny 96
    Let's suppose I have an array: bool eleme[1000000] = {false}; and at some point in my code I change some of the first of the n elements of this array to true. Afterwards I want to be sure that all elements of the array are false. So I do: for (int i =0; i < n; ++i) eleme[i] = false; which costs T(n). Is there a way to do this in constant time? E.g. something like make_false(eleme, n);

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  • How do you detach an array of strings from shared memory? C

    - by Tim
    I have: int array_id; char* records[10]; // get the shared segment if ((array_id = shmget(IPC_PRIVATE, 1, 0666)) == -1) { perror("Array Creating"); } // attach records[0] = (char*) shmat(array_id, (void*)0, 0); if ((int) *records == -1) { perror("Array Attachment"); } which works fine, but when i try and detach i get an "invalid argument" error. // detach int error; if( (error = shmdt((void*) records[0])) == -1) { perror(array detachment); } any ideas? thank you

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  • How exactly do you use json_decode to pass a javascript array to php?

    - by Adam
    This is how I got my php array to javascript echo 'var daysofweek = '.json_encode($daysofweek).';'; Now I am aware that json_decode can do the opposite, however the problem is I don't know the syntax to do so. I tried: <script> var array_days = new Array(); array_days[] = "psdfo"; array_days[] = "bsdf"; <?php $array_days = json_decode(?>array_days<?php);?> </script> yes im clueless. I forgot to mention that I want to send an array through post, having all my information regarding all the form values dynamically created by javascript. Otherwise, I wouldn't know which name="" to look for as it will be decided by the user. Unless someone else has an alternative solution...

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  • How do I print array values in a range when values are supplied?

    - by dcp3450
    My php reads in xml and I want to ouput the values within a given range. I have no way of knowing the size of the array or the range. However, I do know where to start; I have a $key that holds my current location. I also know where to stop; I have the word "ENDEVENTS" between each set. I want to get the values from my current position ($key) to my end position ("ENDEVENTS"). for example i may have an array set like this: Array( [0]=1 [1]=apple [2]=straw [3]=bike [4]=ENDEVENTS [5]=15 [6]=hair [7]=shirt [8]=nose [9]=kiwi [10]=ENDEVENTS ) My code knows when I'm on 15 (in this example $key=5). I want to print 6 through 9. I tried using foreach but it's thats causing issues with what I'm trying to produce. Any ideas?

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  • Is it possible to auto generate Getter/Setter from Array Values in PHP?

    - by Phill Pafford
    So I have a couple of arrays $array_1 = Array('one','two','three'); $array_2 = Array('red','blue','green'); Is there a dynamic way to create the Setters and Getters for an array with single value entries? So the class would be something like: class xFromArray() { } So the above if I passed $array_1 it would generate something like this: private $one; setOne($x) { $one = $x; } getOne() { return $one; } if I passed $array_2 it would generate something like this: private $red; setRed($x) { $red = $x; } getRed() { return $red; } So I would call it somehow like this? (My best guess but doesn't seem that this would work) $xFromArray = new xFromArray; foreach($array_1 as $key=>$data) { $xFromArray->create_function(set.ucfirst($data)($data)); echo $xFromArray->create_function(get.ucfirst($data)); }

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  • access a property via string with array in php?

    - by sprugman
    (This is in drupal, but I don't really think that matters.) I have a big list of properties that I need to map between two objects, and in one, the value that I need to map is buried inside an array. I'm hoping to avoid hard-coding the property names in the code. If I have a class like this: class Product { public $colors, $sizes; } I can access the properties like this: $props = array('colors', 'sizes'); foreach ($props as $p) { $this->$p = $other_object->$p; } As far as I can tell, if each of the properties on the left are an array, I can't do this: foreach ($props as $p) { $this->$p[0]['value'] = $other_object->$p; } Is that correct, or am I missing some clever way around this?

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  • How do I compare a string in an array to a string?

    - by user1641312
    EDIT: IT'S FIXED, THANKS FOR THE HELP! So basically I have an array of strings, a question and an answer public static String[][] triviaData = { {"Question2", "Answer1"}, {"Question2", "Answer2"}, {"Question3", "Answer3"}, }; And I am trying to make a method that validates an entered input, lets call the entered input enteredAnswer. enteredAnswer is stored as a String. I am trying to validate that the enteredAnswer is the same as the second index of the array. if (enteredAnswer.equalsIgnoreCase(triviaData[Config.CurrentQuestion][1])) { This is the code I tried, but I get the error "Cannot invoke equalsIgnoreCase(String) on the array type String[]" I am a beginner programmer so if you could help me out it would be highly appreciated. Thanks. enteredAnswer is stored as public String[] enteredAnswer;

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  • Solution to Jira web service getWorklogs method error: Object of type System.Xml.XmlNode[] cannot be stored in an array of this type

    - by DigiMortal
    When using Jira web service methods that operate on work logs you may get the following error when running your .NET application: Object of type System.Xml.XmlNode[] cannot be stored in an array of this type. In this posting I will show you solution to this problem. I don’t want to go to deep in details about this problem. I think it’s enough for this posting to mention that this problem is related to one small conflict between .NET web service support and Axis. Of course, Jira team is trying to solve it but until this problem is solved you can use solution provided here. There is good solution to this problem given by Jira forum user Kostadin. You can find it from Jira forum thread RemoteWorkLog serialization from Soap Service in C#. Solution is simple – you have to use SOAP extension class to replace new class names with old ones that .NET found from WSDL. Here is the code by Kostadin. public class JiraSoapExtensions : SoapExtension {     private Stream _streamIn;     private Stream _streamOut;       public override void ProcessMessage(SoapMessage message)     {         string messageAsString;         StreamReader reader;         StreamWriter writer;           switch (message.Stage)         {             case SoapMessageStage.BeforeSerialize:                 break;             case SoapMessageStage.AfterDeserialize:                 break;             case SoapMessageStage.BeforeDeserialize:                 reader = new StreamReader(_streamOut);                 writer = new StreamWriter(_streamIn);                 messageAsString = reader.ReadToEnd();                 switch (message.MethodInfo.Name)                 {                     case "getWorklogs":                     case "addWorklogWithNewRemainingEstimate":                     case "addWorklogAndAutoAdjustRemainingEstimate":                     case "addWorklogAndRetainRemainingEstimate":                         messageAsString = messageAsString.                             .Replace("RemoteWorklogImpl", "RemoteWorklog")                             .Replace("service", "beans");                         break;                 }                 writer.Write(messageAsString);                 writer.Flush();                 _streamIn.Position = 0;                 break;             case SoapMessageStage.AfterSerialize:                 _streamIn.Position = 0;                 reader = new StreamReader(_streamIn);                 writer = new StreamWriter(_streamOut);                 messageAsString = reader.ReadToEnd();                 writer.Write(messageAsString);                 writer.Flush(); break;         }     }       public override Stream ChainStream(Stream stream)     {         _streamOut = stream;         _streamIn = new MemoryStream();         return _streamIn;     }       public override object GetInitializer(Type type)     {         return GetType();     }       public override object GetInitializer(LogicalMethodInfo info,         SoapExtensionAttribute attribute)     {         return null;     }       public override void Initialize(object initializer)     {     } } To get this extension work with Jira web service you have to add the following block to your application configuration file (under system.web section). <webServices>   <soapExtensionTypes>    <add type="JiraStudioExperiments.JiraSoapExtensions,JiraStudioExperiments"           priority="1"/>   </soapExtensionTypes> </webServices> Weird thing is that after successfully using this extension and disabling it everything still works.

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  • How to attach turrets to tiles in a tile based game

    - by Joseph St. Pierre
    I am a flash developer, and I am building a Tower Defense game. The world is being built through tiles, and I have gotten that accomplished easily. I have also gotten level changes and enemy spawning down as well. However, I wish the player to be able to spawn turrets, and have those turrets be on specific tiles, based upon where the player placed it. Here is my code: stop(); colOffset = 50; rowOffset = 50; guns = []; placed = true; dead = 0; spawned = 0; level = 1; interval = 350 / level; amount = level * 20; counter = 0; numCol = 14; numRow = 10; tiles = []; k = 0; create = false; tileName = new Array("road","grass","end", "start"); board = new Array( new Array(1,1,1,1,3,1,1,1,1,1,2,1,1,1), new Array(1,1,1,0,0,1,1,1,1,1,0,1,1,1), new Array(1,1,1,0,1,1,1,1,1,1,0,0,1,1), new Array(1,1,1,0,0,0,1,1,1,1,1,0,1,1), new Array(1,1,1,0,1,0,0,0,1,1,1,0,0,1), new Array(1,1,1,0,1,1,1,0,0,1,1,1,0,1), new Array(1,1,0,0,1,1,1,1,0,1,1,0,0,1), new Array(1,1,0,1,1,1,1,1,0,1,0,0,1,1), new Array(1,1,0,0,0,0,0,0,0,1,0,1,1,1), new Array(1,1,1,1,1,1,1,1,0,0,0,1,1,1) ); buildBoard(); function buildBoard(){ for ( col = 0; col < numCol; col++){ for ( row = 0; row < numRow; row++){ _root.attachMovie("tile", "tile_" + col + "_" + row, _root.getNextHighestDepth()); theTile = eval("tile_" + col + "_" + row); theTile._x = (col * 50); theTile._y = (row * 50); theTile.row = row; theTile.col = col; tileType = board[row][col]; theTile.gotoAndStop(tileName[tileType]); tiles.push(theTile); } } } init(); function init(){ onEnterFrame = function(){ counter += 1; if ( spawned < amount && counter > 50){ min= _root.attachMovie("minion","minion",_root.getNextHighestDepth()); min._x = tile_4_0._x + 25; min._y = tile_4_0._y + 25; min.health = 100; choose = Math.round(Math.random()); if ( choose == 0 ){ min.waypointX = [ tile_4_1._x +25, tile_3_1._x + 25, tile_3_2._x + 25, tile_3_6._x + 25, tile_2_6._x + 25, tile_2_8._x + 25, tile_8_8._x + 25, tile_8_9._x + 25, tile_10_9._x + 25, tile_10_7._x + 25, tile_11_7._x + 25, tile_11_6._x + 25, tile_12_6._x + 25, tile_12_4._x + 25, tile_11_4._x + 25, tile_11_2._x + 25, tile_10_2._x + 25, tile_10_0._x + 25]; min.waypointY = [ tile_4_1._y +25, tile_3_1._y + 25, tile_3_2._y + 25, tile_3_6._y + 25, tile_2_6._y + 25, tile_2_8._y + 25, tile_8_8._y + 25, tile_8_9._y + 25, tile_10_9._y + 25, tile_10_7._y + 25, tile_11_7._y + 25, tile_11_6._y + 25, tile_12_6._y + 25, tile_12_4._y + 25, tile_11_4._y + 25, tile_11_2._y + 25, tile_10_2._y + 25, tile_10_0._y + 25]; } else if ( choose == 1 ){ min.waypointX = [ tile_4_1._x +25, tile_3_1._x + 25, tile_3_2._x + 25, tile_3_3._x + 25, tile_5_3._x + 25, tile_5_4._x + 25, tile_7_4._x + 25, tile_7_5._x + 25, tile_8_5._x + 25, tile_8_8._x + 25, tile_8_9._x + 25, tile_10_9._x + 25, tile_10_7._x + 25, tile_11_7._x + 25, tile_11_6._x + 25, tile_12_6._x + 25, tile_12_4._x + 25, tile_11_4._x + 25, tile_11_2._x + 25, tile_10_2._x + 25, tile_10_0._x + 25 ]; min.waypointY = [ tile_4_1._y +25, tile_3_1._y + 25, tile_3_2._y + 25, tile_3_3._y + 25, tile_5_3._y + 25, tile_5_4._y + 25, tile_7_4._y + 25, tile_7_5._y + 25, tile_8_5._y + 25, tile_8_8._y + 25, tile_8_9._y + 25, tile_10_9._y + 25, tile_10_7._y + 25, tile_11_7._y + 25, tile_11_6._y + 25, tile_12_6._y + 25, tile_12_4._y + 25, tile_11_4._y + 25, tile_11_2._y + 25, tile_10_2._y + 25, tile_10_0._y + 25 ]; } min.i = 0; counter = 0; spawned += 1; min.onEnterFrame = function(){ dx = this.waypointX[this.i] - this._x; dy = this.waypointY[this.i] - this._y; radians = Math.atan2(dy,dx); degrees = radians * 180 / Math.PI; xspeed = Math.cos(radians); yspeed = Math.sin(radians); this._x += xspeed; this._y += yspeed; if( this._x == this.waypointX[this.i] && this._y == this.waypointY[this.i]){ this.i++; } if ( this._x == tile_10_0._x + 25 && this._y == tile_10_0._y + 25){ this.removeMovieClip(); dead += 1; } } } if ( dead >= amount ){ dead = 0; level += 1; amount = level * 20; spawned = 0; } } btnM.onRelease = function(){ create = true; } } game.onEnterFrame = function(){ } It is possible for me however to complete this task, but only once. I am able to make the turret, drag it over to a tile, and have it attach itself to the tile. No problem. The issue is, I cannot do these multiple times. Please Help.

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  • Internal Mutation of Persistent Data Structures

    - by Greg Ros
    To clarify, when I mean use the terms persistent and immutable on a data structure, I mean that: The state of the data structure remains unchanged for its lifetime. It always holds the same data, and the same operations always produce the same results. The data structure allows Add, Remove, and similar methods that return new objects of its kind, modified as instructed, that may or may not share some of the data of the original object. However, while a data structure may seem to the user as persistent, it may do other things under the hood. To be sure, all data structures are, internally, at least somewhere, based on mutable storage. If I were to base a persistent vector on an array, and copy it whenever Add is invoked, it would still be persistent, as long as I modify only locally created arrays. However, sometimes, you can greatly increase performance by mutating a data structure under the hood. In more, say, insidious, dangerous, and destructive ways. Ways that might leave the abstraction untouched, not letting the user know anything has changed about the data structure, but being critical in the implementation level. For example, let's say that we have a class called ArrayVector implemented using an array. Whenever you invoke Add, you get a ArrayVector build on top of a newly allocated array that has an additional item. A sequence of such updates will involve n array copies and allocations. Here is an illustration: However, let's say we implement a lazy mechanism that stores all sorts of updates -- such as Add, Set, and others in a queue. In this case, each update requires constant time (adding an item to a queue), and no array allocation is involved. When a user tries to get an item in the array, all the queued modifications are applied under the hood, requiring a single array allocation and copy (since we know exactly what data the final array will hold, and how big it will be). Future get operations will be performed on an empty cache, so they will take a single operation. But in order to implement this, we need to 'switch' or mutate the internal array to the new one, and empty the cache -- a very dangerous action. However, considering that in many circumstances (most updates are going to occur in sequence, after all), this can save a lot of time and memory, it might be worth it -- you will need to ensure exclusive access to the internal state, of course. This isn't a question about the efficacy of such a data structure. It's a more general question. Is it ever acceptable to mutate the internal state of a supposedly persistent or immutable object in destructive and dangerous ways? Does performance justify it? Would you still be able to call it immutable? Oh, and could you implement this sort of laziness without mutating the data structure in the specified fashion?

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  • Why unhandled exceptions are useful

    - by Simon Cooper
    It’s the bane of most programmers’ lives – an unhandled exception causes your application or webapp to crash, an ugly dialog gets displayed to the user, and they come complaining to you. Then, somehow, you need to figure out what went wrong. Hopefully, you’ve got a log file, or some other way of reporting unhandled exceptions (obligatory employer plug: SmartAssembly reports an application’s unhandled exceptions straight to you, along with the entire state of the stack and variables at that point). If not, you have to try and replicate it yourself, or do some psychic debugging to try and figure out what’s wrong. However, it’s good that the program crashed. Or, more precisely, it is correct behaviour. An unhandled exception in your application means that, somewhere in your code, there is an assumption that you made that is actually invalid. Coding assumptions Let me explain a bit more. Every method, every line of code you write, depends on implicit assumptions that you have made. Take this following simple method, that copies a collection to an array and includes an item if it isn’t in the collection already, using a supplied IEqualityComparer: public static T[] ToArrayWithItem( ICollection<T> coll, T obj, IEqualityComparer<T> comparer) { // check if the object is in collection already // using the supplied comparer foreach (var item in coll) { if (comparer.Equals(item, obj)) { // it's in the collection already // simply copy the collection to an array // and return it T[] array = new T[coll.Count]; coll.CopyTo(array, 0); return array; } } // not in the collection // copy coll to an array, and add obj to it // then return it T[] array = new T[coll.Count+1]; coll.CopyTo(array, 0); array[array.Length-1] = obj; return array; } What’s all the assumptions made by this fairly simple bit of code? coll is never null comparer is never null coll.CopyTo(array, 0) will copy all the items in the collection into the array, in the order defined for the collection, starting at the first item in the array. The enumerator for coll returns all the items in the collection, in the order defined for the collection comparer.Equals returns true if the items are equal (for whatever definition of ‘equal’ the comparer uses), false otherwise comparer.Equals, coll.CopyTo, and the coll enumerator will never throw an exception or hang for any possible input and any possible values of T coll will have less than 4 billion items in it (this is a built-in limit of the CLR) array won’t be more than 2GB, both on 32 and 64-bit systems, for any possible values of T (again, a limit of the CLR) There are no threads that will modify coll while this method is running and, more esoterically: The C# compiler will compile this code to IL according to the C# specification The CLR and JIT compiler will produce machine code to execute the IL on the user’s computer The computer will execute the machine code correctly That’s a lot of assumptions. Now, it could be that all these assumptions are valid for the situations this method is called. But if this does crash out with an exception, or crash later on, then that shows one of the assumptions has been invalidated somehow. An unhandled exception shows that your code is running in a situation which you did not anticipate, and there is something about how your code runs that you do not understand. Debugging the problem is the process of learning more about the new situation and how your code interacts with it. When you understand the problem, the solution is (usually) obvious. The solution may be a one-line fix, the rewrite of a method or class, or a large-scale refactoring of the codebase, but whatever it is, the fix for the crash will incorporate the new information you’ve gained about your own code, along with the modified assumptions. When code is running with an assumption or invariant it depended on broken, then the result is ‘undefined behaviour’. Anything can happen, up to and including formatting the entire disk or making the user’s computer sentient and start doing a good impression of Skynet. You might think that those can’t happen, but at Halting problem levels of generality, as soon as an assumption the code depended on is broken, the program can do anything. That is why it’s important to fail-fast and stop the program as soon as an invariant is broken, to minimise the damage that is done. What does this mean in practice? To start with, document and check your assumptions. As with most things, there is a level of judgement required. How you check and document your assumptions depends on how the code is used (that’s some more assumptions you’ve made), how likely it is a method will be passed invalid arguments or called in an invalid state, how likely it is the assumptions will be broken, how expensive it is to check the assumptions, and how bad things are likely to get if the assumptions are broken. Now, some assumptions you can assume unless proven otherwise. You can safely assume the C# compiler, CLR, and computer all run the method correctly, unless you have evidence of a compiler, CLR or processor bug. You can also assume that interface implementations work the way you expect them to; implementing an interface is more than simply declaring methods with certain signatures in your type. The behaviour of those methods, and how they work, is part of the interface contract as well. For example, for members of a public API, it is very important to document your assumptions and check your state before running the bulk of the method, throwing ArgumentException, ArgumentNullException, InvalidOperationException, or another exception type as appropriate if the input or state is wrong. For internal and private methods, it is less important. If a private method expects collection items in a certain order, then you don’t necessarily need to explicitly check it in code, but you can add comments or documentation specifying what state you expect the collection to be in at a certain point. That way, anyone debugging your code can immediately see what’s wrong if this does ever become an issue. You can also use DEBUG preprocessor blocks and Debug.Assert to document and check your assumptions without incurring a performance hit in release builds. On my coding soapbox… A few pet peeves of mine around assumptions. Firstly, catch-all try blocks: try { ... } catch { } A catch-all hides exceptions generated by broken assumptions, and lets the program carry on in an unknown state. Later, an exception is likely to be generated due to further broken assumptions due to the unknown state, causing difficulties when debugging as the catch-all has hidden the original problem. It’s much better to let the program crash straight away, so you know where the problem is. You should only use a catch-all if you are sure that any exception generated in the try block is safe to ignore. That’s a pretty big ask! Secondly, using as when you should be casting. Doing this: (obj as IFoo).Method(); or this: IFoo foo = obj as IFoo; ... foo.Method(); when you should be doing this: ((IFoo)obj).Method(); or this: IFoo foo = (IFoo)obj; ... foo.Method(); There’s an assumption here that obj will always implement IFoo. If it doesn’t, then by using as instead of a cast you’ve turned an obvious InvalidCastException at the point of the cast that will probably tell you what type obj actually is, into a non-obvious NullReferenceException at some later point that gives you no information at all. If you believe obj is always an IFoo, then say so in code! Let it fail-fast if not, then it’s far easier to figure out what’s wrong. Thirdly, document your assumptions. If an algorithm depends on a non-trivial relationship between several objects or variables, then say so. A single-line comment will do. Don’t leave it up to whoever’s debugging your code after you to figure it out. Conclusion It’s better to crash out and fail-fast when an assumption is broken. If it doesn’t, then there’s likely to be further crashes along the way that hide the original problem. Or, even worse, your program will be running in an undefined state, where anything can happen. Unhandled exceptions aren’t good per-se, but they give you some very useful information about your code that you didn’t know before. And that can only be a good thing.

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  • PHP class data implementation

    - by Bakanyaka
    I'm studying OOP PHP and have watched two tutorials that implement user login\registration system as an example. But implementation varies. Which way will be more correct one to work with data such as this? Load all data retrieved from database as array into a property called something like _data on class creation and further methods operate with this property Create separate properties for each field retrieved from database, on class creation load all data fields into respective properties and operate with that properties separately? Then let's say I want to create a method that returns a list of all users with their data. Which way is better? Method that returns just an array of userdata like this: Array([0]=>array([id] => 1, [username] => 'John', ...), [1]=>array([id] => 2, [username] => 'Jack', ...), ...) Method that creates a new instance of it's class for each user and returns an array of objects

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  • C# struct and NuSOAP(php)

    - by opx
    Hello Im trying to build a client in c# that talks with some remote (php)server with SOAP using the NuSOAP library. Here im using a struct/object that will containt the user info of some user: public struct UserProfile { public string username; public string password; public string email; public string site; public string signature; public int age; public int points; And this is the PHP Code: server->wsdl->addComplexType( 'UserProfile', 'complexType', 'struct', 'all', '', array( 'username' => array('name' => 'username', 'type' => 'xsd:string'), 'password' => array('name' => 'password', 'type' => 'xsd:string'), 'email' => array('name' => 'email', 'type' => 'xsd:string'), 'site' => array('name' => 'site', 'type' => 'xsd:string'), 'signature' => array('name' => 'signature', 'type' => 'xsd:string'), 'age' => array('name' => 'age', 'type' => 'xsd:int'), 'points' => array('name' => 'username', 'type' => 'xsd:int'), ) ); $server->wsdl->addComplexType( 'UserProfileArray', 'complexType', 'array', '', 'SOAP-ENC:Array', array(), array(array('ref' => 'SOAP-ENC:arrayType', 'wsdl:arrayType' => 'tns:UserProfile[]')), 'tns:UserProfile' ); $server->register("getUserProfile", array(), array('return' => 'tns:UserProfileArray'), $namespace, false, 'rpc', false, 'Get the user profile object' ); function getUserProfile(){ $profile['username'] = "user"; $profile['password'] = "pass"; $profile['email'] = "usern@ame"; $profile['site'] = "u.com"; $profile['signature'] = "usucsdckme"; $profile['age'] = 111; $profile['points'] = time() / 2444; return $profile; } Now I already have a working login function, and I want to get the info about the logged in user but I dont know howto obtain these. This is what im using to get the userinfo: string user = txtUser.Text; string pass = txtPass.Text; SimpleService.SimpleService service = new SimpleService.SimpleService(); if(service.login(user, pass)){ //logged in } SoapApp.SimpleService.UserProfile[] user = service.getUserProfile(); // THIS LINE GIVES ME AN EXCEPTION MessageBox.Show(user[0].username + "--" + user[0].points); The getUserProfile() function produces an error: System.Web.Services.Protocols.SoapException was unhandled Message="unable to serialize result" Source="System.Web.Services" or I get something like 'cant parse xml' error. The article I used for this was from: http://www.sanity-free.org/125/php_webservices_and_csharp_dotnet_soap_clients.html The difference on what they are doing and what I try to do is that I only want to get one object returned instead of multiple 'MySoapObjects'. I hope someone is familiar with this and could help me, thanks in advance! Regards, opx

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  • How to save data from multiple views of an iPhone app?

    - by DownUnder
    Hi Everyone. I'm making an app where I need to save the text in multiple views in the app when the app quits. I also need to be able to remove all of the data from just one of those views and when the app quits, it's possible not all of those views will have been created yet. After reading this post I thought perhaps it would be good to use a singleton that manages my app data which loads in the data when it is first requested and saved it when the app quits. Then in each view where I need to save data I can just set it on the singleton. I gave it a go but have run into some issues. At first I didn't synthesize the properties (as in the post I was using as a guide) but the compiler told me I needed to make getters and setters, so I did. Now when my applicationWIllTerminate: gets call the app crashes and the console says "Program received signal: “EXC_BAD_ACCESS”. kill quit". Is anyone able to tell me what I'm doing wrong, or suggest a better approach to saving the data? //SavedData.h #import <Foundation/Foundation.h> #define kFileName @"appData.plist" @interface SavedData : NSObject { NSString *information; NSString *name; NSString *email; NSString *phone; NSString *mobile; } @property(assign) NSString *information; @property(assign) NSString *name; @property(assign) NSString *email; @property(assign) NSString *phone; @property(assign) NSString *mobile; + (SavedData *)singleton; + (NSString *)dataFilePath; + (void)applicationWillTerminate:(NSNotification *)notification; @end //SavedData.m #import "SavedData.h" @implementation SavedData @synthesize information; @synthesize name; @synthesize email; @synthesize phone; @synthesize mobile; static SavedData * SavedData_Singleton = nil; + (SavedData *)singleton{ if (nil == SavedData_Singleton){ SavedData_Singleton = [[SavedData_Singleton alloc] init]; NSString *filePath = [self dataFilePath]; if([[NSFileManager defaultManager] fileExistsAtPath:filePath]){ NSMutableArray * array = [[NSMutableArray alloc] initWithContentsOfFile:filePath]; information = [array objectAtIndex:0]; name = [array objectAtIndex:1]; email = [array objectAtIndex:2]; phone = [array objectAtIndex:3]; mobile = [array objectAtIndex:4]; [array release]; } UIApplication *app = [UIApplication sharedApplication]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillTerminate:) name:UIApplicationWillTerminateNotification object:app]; } return SavedData_Singleton; } + (NSString *)dataFilePath{ NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *DocumentsDirectory = [paths objectAtIndex:0]; return [DocumentsDirectory stringByAppendingPathComponent:kFileName]; } + (void)applicationWillTerminate:(NSNotification *)notification{ NSLog(@"Application will terminate received"); NSMutableArray *array = [[NSMutableArray alloc] init]; [array addObject:information]; [array addObject:name]; [array addObject:email]; [array addObject:phone]; [array addObject:mobile]; [array writeToFile:[self dataFilePath] atomically:YES]; [array release]; } @end Then when I want to use it I do myLabel.text = [SavedData singleton].information; And when I change the field [SavedData singleton].information = @"my string"; Any help will be very much appreciated!

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  • Adding picture in symfony 2 from symfony form?

    - by user2833510
    How do I add a picture in symfony2 from form to a database. I want to make a logo as a picture field and store project picture in database from form. How do I do this? Here is my form: <?php namespace Projects\ProjectsBundle\Form; use Symfony\Component\Form\AbstractType; use Symfony\Component\Form\FormBuilderInterface; use Symfony\Component\OptionsResolver\OptionsResolverInterface; class ProjectsType extends AbstractType { public function buildForm(FormBuilderInterface $builder, array $options) { $builder ->add('name') ->add('description') ->add('priority','choice', array( 'choices' => array('high' => 'high', 'low' => 'low', 'medium' => 'medium'))) ->add('logo') ->add('startedAt','datetime',array('label' => false,'data'=>new \DateTime(),'attr'=>array('style'=>'display:none;'))) ->add('completedOn','datetime',array('label' => false,'data'=>new \DateTime(),'attr'=>array('style'=>'display:none;'))) ->add('createdDatetime','datetime',array('label' => false,'data'=>new \DateTime(),'attr'=>array('style'=>'display:none;'))) ->add('updatedDatetime','datetime',array('label' => false,'data'=>new \DateTime(),'attr'=>array('style'=>'display:none;'))) ; } public function setDefaultOptions(OptionsResolverInterface $resolver) { $resolver->setDefaults(array( 'data_class' => 'Projects\ProjectsBundle\Entity\Projects' )); } public function getName() { return 'projects_projectsbundle_projectstype'; } } and here is my controller: public function createAction(Request $request) { $user = $this->get('security.context')->getToken()->getUser(); $userId = $user->getId(); $entity = new Projects(); $form = $this->createForm(new ProjectsType(), $entity); $form->bind($request); $entity->setCreatedBy($userId); $entity->setUpdatedBy($userId); $entity->setCompletedBy($userId); if ($form->isValid()) { $em = $this->getDoctrine()->getManager(); $em->persist($entity); $em->flush(); $_SESSION['projectid'] =$entity->getId(); if($request->isXmlHttpRequest()) { $response = new Response(); $output = array('success' => true, 'description' => $entity->getdescription(), 'id' => $entity->getId(), 'name' => $entity->getname(), 'priority' => $entity->getpriority(), 'logo' => $entity->getlogo(), 'startedat' => $entity->getstartedat(),'completedon' => $entity->getcompletedon(),'completedby' => $entity->getCompletedBy(), 'createdby' => $entity->getcreatedby(), 'updatedby' => $entity->getupdatedby(), 'createddatetime' => $entity->getcreateddatetime(), 'updateddatetime' => $entity->getupdateddatetime()); $response->headers->set('Content-Type', 'application/json'); $response->setContent(json_encode($output)); return $response; } return $this->redirect($this->generateUrl('projects_show', array('id' => $entity->getId()))); } return $this->render('ProjectsProjectsBundle:Projects:new.html.twig', array( 'entity' => $entity, 'form' => $form->createView(), )); }

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