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• I asked a question about arrays before, but this one won't compile

  - by unit

  I asked about this array a little while ago, and I can't see what the problem is. Too tired. What have I done wrong? Basically, I am taking a string array and trying to check to see if it contains numbers or an x (ISBN number validation). I want to take the number from a given input (bookNum), check the input, and feed any valid input into a new array (book). At the line 'bookNum.charAt[j]==book[i]' I get the 'not a statement error'. What gives? String[] book = new String [ISBN_NUM]; bookNum.replaceAll("-",""); if (bookNum.length()!=ISBN_NUM) throw new ISBNException ("ISBN "+ bookNum + " must be 10 characters"); for (int i=0;i<bookNum.length();i++) { if (Character.isDigit(bookNum.charAt(i))) bookNum.CharAt[j]==book[i]; j++; if (book[9].isNotDigit()|| book[9]!="x" || book[9]!="X") throw new ISBNException ("ISBN " + bookNum + " must contain all digits" + "or 'X' in the last position");

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• Beginner question about getting reference to cin

  - by John C

  I'm having problems wrapping my head around this. I have a function void foo(istream& input) { input = cin; } This fails (I'm assuming because cin isn't supposed to be "copyable". however, this works void foo(istream& input) { istream& baz = cin; } Is there a reason that I can get a reference to cin in baz but I cannot assign it to input? Thanks

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• fstream file I/O question

  - by Konrad

  Hi, I am trying to work out if I need to call close on a fstream object if the intial open failed. i.e. std::fstream strm; strm.open( "filename" ); if( ! strm.fail() ) { // Do something strm.close(); // [1] } strm.close(); // [2] Where should close be called here - should it always be called [2] or only if the open succeeds[1]? I may be going over the top here, but coming from the Windows API way of typically doing this I have CloseHandle( ... ); embedded in my mind :-)

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• Code casing question for private class fields

  - by user200295

  Take the following example public class Class1{ public string Prop1{ get {return m_Prop1;} set {m_Prop1 = value; } } private string m_Prop1; // this is standard private property variable name // how do we cap this variable name? While the compiler can figure out same casing // it makes it hard to read private Class2 Class2; // we camel case the parameter public Class1(Class2 class2){ this.Class2 = class2; } } Here are my stock rules The class name is capitalized (Class1) The public properties are capitalized (Prop1) The private field tied to a public property has m_ to indicate this. My coworker prefers _ There is some debate if using m_ or _ should be used at all, as it is like Hungarian notation. Private class fields are capitalized. The part I am trying to figure out is what do I do if when the Class name of a private field matches the private field name. For example, private Class2 Class2; This is confusing. If the private field name is not the same class, for example private string Name; , there isn't much issue. Or am I thinking about the issue wrong. Should my classes and private fields be named in such a way that they don't collide?

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• JSF templating beginner's question.

  - by Nitesh Panchal

  Hello, I belong to Asp.Net but just starting to learn JSF. I wanted to know whether all features of MasterPage are available in JSF templating? I mean say suppose i have a menu in template, and based on roles menu changes. If the Admin logs in, he will get to show more options and if general user logs in he will get to see less options. Now i have a managed bean for my "real" page(not template). How do i use this managed bean to toggle my control in template on and Off?

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• Question on different ways to link tables

  - by dotnetdev

  What is the difference between linking two tables and then the PK is an FK in the other table, but the FK has not got the primary key option (so it does not have the gold key), and having the PK in one table as a PK in another table? Am I right to think that the second option is for a many-to-many relationship? Thanks

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• C++ pointer to functions, Beginner Question...

  - by BobAlmond

  Hi all, I want to ask about pointer in C++ I have some simple code: int add(int a, int b){ return a+b; } int runner(int x,int y, int (*functocall)(int, int)){ return (*functocall)(x,y); } now, suppose I call those functions using this way : cout<<runner(2,5,&add); or maybe cout<<runner(2,5,add); is there any difference? because when I tried, the result is the same and with no error. Thanks a lot

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• Python Class Variables Question

  - by zyq524

  I have some doubt about python's class variables. As my understanding, if I define a class variable, which is declared outside the init() function, this variable will create only once as a static variable in C++. This seems right for some python types, for instance, dict and list type, but for those base type, e.g. int,float, is not the same. For example: class A: dict1={} list1=list() int1=3 def add_stuff(self, k, v): self.dict1[k]=v self.list1.append(k) self.int1=k def print_stuff(self): print self.dict1,self.list1,self.int1 a1 = A() a1.add_stuff(1, 2) a1.print_stuff() a2=A() a2.print_stuff() The output is: {1: 2} [1] 1 {1: 2} [1] 3 I understand the results of dict1 and list1, but why does int1 behavior different?

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• View Controller Question

  - by user341444

  First off I'm new at programming. I'm creating an app with one navigation bar controller. The app is pretty basic except for a quiz section that is comprised of 12 xibs. As the users takes the quiz a new xib is pushed onto the stack. I want to create a button that takes the user back to the home screen if they do not want to complete the quiz. The back button takes them to the previous xib which could be 11 deep. Is it possible to dismiss the modal views and reload the rootView controller? Here's the code from my delegate @synthesize window; @synthesize navigationController; (void)applicationDidFinishLaunching:(UIApplication *)application { // Override point for customization after application launch [window addSubview:[navigationController view]]; [window makeKeyAndVisible]; } (void)dealloc { [window release]; [navigationController release]; [super dealloc]; } This is how I'm pushing new xibs onto the stack (IBAction) showTesting: (id)sender { Testing *varTesting = [[[Testing alloc] initWithNibName:@"Testing" bundle:nil] autorelease]; [[self navigationController] pushViewController:varTesting animated: YES]; } Any help would be greatly appreciated. Thanks

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• Twitter OAuth question

  - by Squall

  Hi there, I'm making a Twitter client in Java, and I've came to a problem I don't know how to solve it. How the hell I store open auth for twitter? I mean it doesn't make very sense for a person to allow an application every time he wants to use the client. I've been look at the Twitter documentation, but I must say, it's really poor in terms of Java. So do you guy have some idea to solve this? Thanks in advance!

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• Question about fwrite API

  - by michael

  Hi, In C++, there is a fwrite() which writes a buffer to a file on disk: http://www.cplusplus.com/reference/clibrary/cstdio/fwrite/ Can you please tell me if there is any buffer inside that fwrite implementation? i.e. if I call fwrite() multiple times (say 10 times), does it actually invoke file i/o 10 different times? Thank you.

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• Best practice question

  - by sid_com

  Hello! Which version would you prefer? #!/usr/bin/env perl use warnings; use strict; use 5.010; my $p = 7; # 33 my $prompt = ' : '; my $key = 'very important text'; my $value = 'Hello, World!'; my $length = length $key . $prompt; $p -= $length; Option 1: $key = $key . ' ' x $p . $prompt; Option 2: if ( $p > 0 ) { $key = $key . ' ' x $p . $prompt; } else { $key = $key . $prompt; } say "$key$value"

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• C++: Short question regarding switch and break

  - by oh boy

  Example: switch( x ) { case y: if ( true ) { break; } cout << "Oops"; break; } If the switch statement selects y, will Oops be written to the standard output? - Is break in switch statements a dynamic keyword like continue which can be called under conditions or static like a closing bracket }?

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• Question about python modules

  - by morpheous

  I have recently started learning Python and I have 2 questions relating to modules. Is there a way to obtain a list of Python modules available (i.e. installed) on a mchine? I am using Ubuntum Karmic and Synaptic for package management. I have just installed a python module.Where is the module code actually stored on my machine? (is there a default [recommended] location that modules are stored)?

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• Question about JavaScript syntax

  - by Sakti

  $(document).ready(function(){ var date = new Date(); var d = date.getDate(); var m = date.getMonth(); var y = date.getFullYear(); var month = new array("January","February","March","April","May","June","July","August","September","October","November","December"); var mon; mon = month(m); var today = m+"/"+d+"/"+y $('#calendar').append('<div id="today">Today is'+' '+mon+'/'+d+'/'+y+'.'); });

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• Simple PHP query question: LIKE

  - by pg

  When I replace $ordering = "apples, bananas, cranberries, grapes"; with $ordering = "apples, bananas, grapes"; I no longer want cranberries to be returned by my query, which I've written out like this: $query = "SELECT * from dbname where FruitName LIKE '$ordering'"; Of Course this doesn't work, because I used LIKE wrong. I've read through various manuals that describe how to use LIKE and it doesn't quite make sense to me. If I change the end of the db to "LIKE "apples"" that works for limiting it to just apples. Do I have to explode the ordering on the ", " or is there a way to do this in the query?

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• C++ Memory allocation question involving vectors

  - by TheFuzz

  vector< int > vect; int *int_ptr = new int(10); vect.push_back( *int_ptr ); I under stand that every "new" needs to be followed by a "delete" at some point but does the clear() method clean this memory? What about this method of doing the same thing: vector< int > vect; int int_var = 10; vect.push_back( int_var ); From what I understand, clear() calls the variables destructors, but both vect.push_back() methods in this example push an object on the vector, not a pointer. so does the first example using an int pointer need something other than clear() to clean up memory?

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• Basic question on c++ header file inclusion ?

  - by siva

  What are the differences between below 3 programs ?. Is <iostream> a header file or C++ standard library ? 1 #include<iostream> using namespace std; int main() { return 0; } 2 #include<iostream> int main() { return 0; } 3 #include<iostream.h> int main() { return 0; } Thanks in advance.

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• question about siftdown operation on heap

  - by davit-datuashvili

  i have following pseudo code which execute siftdown operation on heap array suppose is x void siftdown(int n) pre heap(2,n) && n>=0 post heap(1,n) i=1; loop /*invariant heap(1,n) except perhaps between i and it's (0,1,or 2) children*/ c=2*i; if (c>n) break; // c is left child of i if (c+1)<=n /* c+1 is rigth child of i if (x[c+1]<x[c]) c++ /* c is lesser child of i if (x[i]<=x[c]) break; swap(c,i) i=c; i have wrote following code is it correct? public class siftdown{ public static void main(String[]args){ int c; int n=9; int a[]=new int[]{19,100,17,2,7,3,36,1,25}; int i=1; while (i<n){ c=2*i; if (c>n) break; //c is the left child of i if (c+1<=n) //c+1 ir rigth child of i if (a[c+1]<a[c]) c++; if (a[i]<=a[c]) break; int t=a[c]; a[c]=a[i]; a[i]=t; i=c; } for (int j=0;j<a.length;j++){ System.out.println(a[j]); } } } // result is 19 2 17 1 7 3 36 100 25

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• question on find value in array

  - by davit-datuashvili

  i have seen a few days ago such problem there is given two array find elements which are common of these array one of the solution was sort big array and then use binary search algorithm and also there is another algorithm- brute-force algorithm for (int i=0;i<array1.length;i++){ for (int j=0;j<array2.length;j++){ if (array1[i]==array2[j]){ //code here } } it's complexity is O(array1.length*array2.length); and i am interested the first method's complexity is also same yes? because we should sort array first and then use search method binary search algorithm's complexity is log_2(n) so it means that total time will be array.length*log_2(n) and about sort? please explain me which is better

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• Question about inserting/updating rows with SQL Server (ASP.NET MVC)

  - by Alex

  I have a very big table with a lot of rows, every row has stats for every user for certain days. And obviously I don't have any stats for future. So to update the stats I use UPDATE Stats SET Visits=@val WHERE ... a lot of conditions ... AND Date=@Today But what if the row doesn't exist? I'd have to use INSERT INTO Stats (...) VALUES (Visits=@val, ..., Date=@Today) How can I check if the row exists or not? Is there any way different from doing the COUNT(*)? If I fill the table with empty cells, it'd take hundreds of thousands of rows taking megabytes and storing no data.

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• excel quotes in formula question

  - by I__

  i have a column with this data: IT_AMPH IT_BARB IT_BENZ IT_BUP SOMA i want the column next to it to be literarely =like "*,IT_AMPH,*" =like "*,IT_BARB,*" =like "*,IT_BENZ,*" etc please note that i want the equal signed to be displayed, exactly as shown above what would be the formula for this?

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• Unable to import example projects from book (newbie question)

  - by StayWett

  I am trying to import projects from a book "Beginning Android 2" but when I choose the root directory the "Finish" button is still grayed out. I've tried importing the project from scratch with no success, and I've also tried to create a template project with the same name and everything and then importing into that (Import existing projects into workspace) but it always says "No projects are found to import". The contents of the folder are: Res folder, src folder with .java file, the manifest, build, and default.properties files. I am new to android dev (obviously) so I appreciate the help.

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• 2 Minute question - HTML / CSS If div within div expands expand parent div

  - by Ozaki

  I have a setup lets say like follows: <div id="nav"> <div id="innernav"> //With dynamic content here. </div> </div> I am running a script that sizes #nav to the size of the browser window in height. But sometimes my dynamic content is now getting bigger than the height of the window.. Is there a way I can enforce that when #innernav exceeds #nav that #nav will increase in size?

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• SVN Version Rollback Question

  - by phimuemue

  Hello, I'm using SVN (TortoiseSVN) and often came into the following situation: I wanted to discard any changes since a specific (old) revision and turn all files back to this specific (old) version. Then I wanted to work further as if this specific (old) revision was the newest one, i.e. I wanted to be able to commit the specific old revision as a new revision. I found several solutions for this problem (for example stackoverflow.com/questions/402159/roll-back-or-revert-entire-svn-repository-to-an-older-revision or rustyrazorblade.com/2007/04/how-to-roll-back-commits-to-an-earlier-version-of-a-repository-in-svn/). However, I wonder if there is a simple way to roll back to a specific revision. I thought version control is just good for such things (or am I misunderstanding something?). Is there a simple command/button/etc. that takes an updates my local repository to an old revision and declares it to be the newest one? Since I suppose that there is no "built-in" function to do this, I wanted to know what reason lead the developers to the decision not to integrate this feature. Does anybody know this?

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