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• Why is the return type not considered when differentiating methods?

  - by Silent Warrior

  The compiler does not consider return type when differentiating methods, so you cannot declare two methods with the same signature even if they have a different return type. Java Tutorial Why is this?

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• Overload the behavior of count() when called on certain objects

  - by Tom

  In PHP 5, you can use magic methods, overload some classes, etc. In C++, you can implement functions that exist is STL as long as the argument types are different. Is there a way to do this in PHP? An example of what I'd like to do is this: class a { function a() { $this->list = array("1", "2"); } } $blah = new a(); count($blah); I would like blah to return 2. IE count the values of a specific array in the class. So in C++, the way I would do this might look like this: int count(a varName) { return count(varName->list); } Basically, I am trying to simplify data calls for a large application so I can call do this: count($object); rather than count($object->list); The list is going to be potentially a list of objects so depending on how it's used, it could be really nasty statement if someone has to do it the current way: count($object->list[0]->list[0]->list); So, can I make something similar to this: function count(a $object) { count($object->list); } I know PHP's count accepts a mixed var, so I don't know if I can override an individual type.

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• Java: If I overwrite the .equals method, can I still test for reference equality with ==?

  - by shots fired

  I have the following situation: I need to sort trees based by height, so I made the Tree's comparable using the height attribute. However, I was also told to overwrite the equals and hashCode methods to avoid unpredictable behaviour. Still, sometimes I may want to compare the references of the roots or something along those lines using ==. Is that still possible or does the == comparison call the equals method?

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• Who can give me a link for the operator= of vector in MSDN?

  - by 8888q8888

  Who can give me a link for the operator= of vector in MSDN? Why I can only find operator[]? If operator= is just something default, like copy everything in A to B, how this following code works? vector<double> v(100,1); v = vector<double>(200,2); // if operator= is just a trivail version, how to make sure the old v get cleared?

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• Solaris syslog.conf. What are root and operator?

  - by cjavapro

  In /etc/syslog.conf #ident "@(#)syslog.conf 1.5 98/12/14 SMI" /* SunOS 5.0 */ # # Copyright (c) 1991-1998 by Sun Microsystems, Inc. # All rights reserved. # # syslog configuration file. # # This file is processed by m4 so be careful to quote (`') names # that match m4 reserved words. Also, within ifdef's, arguments # containing commas must be quoted. # *.err;kern.notice;auth.notice /dev/sysmsg *.err;kern.debug;daemon.notice;mail.crit /var/adm/messages *.alert;kern.err;daemon.err operator *.alert root *.emerg * # if a non-loghost machine chooses to have authentication messages # sent to the loghost machine, un-comment out the following line: #auth.notice ifdef(`LOGHOST', /var/log/authlog, @loghost) mail.debug ifdef(`LOGHOST', /var/log/syslog, @loghost) # # non-loghost machines will use the following lines to cause "user" # log messages to be logged locally. # ifdef(`LOGHOST', , user.err /dev/sysmsg user.err /var/adm/messages user.alert `root, operator' user.emerg * ) I googled some and it seems that root and operator mean email to root and to operator. Is this correct?

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• Do something by operator dial specified number in Asterisk?

  - by Rev

  I want to make ability for Asterisk phone Operators to able do something like this: While operator talking to caller, if Operator dial specified number like 244 (or something like that but not Sip-Userid's), do something (like play sound for caller or etc) for that call. So, Is this possible? Is need to change dialplan? ¦¦¦¦¦ I found this. in first paragraph it's say someething like: if operator dial exten go voiceMail.

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• What is the most concise, unambiguous syntax for operator associated methods (for overloading etc.) that doesn't pollute the namespace?

  - by Doug Treadwell

  Python tends to add double underscores before its built-in or overloadable operator methods, like __add(), whereas C++ requires declaring overloaded operators as operator + (Thing& thing) { /* code */ } for example. Personally I like the operator syntax because it seems to be more explicit and keeps these operator overloading methods separated from other methods without introducing weird prefix notation. What are your thoughts? Also, what about the case of built-in methods that are needed for the programming language to work properly? Is name mangling (like adding __ prefix or sys or something) the best solution here? What do you think about having another type of method declaration, like ... "system method" for lack of creativity at the moment. So there would be two kinds of declarations: int method_name() { ... } system int method_name() { ... } ... and the call would need to be different to distinguish between them. obj.method_name(); vs obj:method_name(); perhaps, assuming a language where : can be unambiguously used in this situation. obj.method_name() vs obj.(system method_name)() Sure, the latter is ugly, but the idea is to make the common case simple and system stuff should be kept out of the way. Maybe the Objective-C notation of method calls? [obj method_name]? Are there more alternatives? Please make suggestions.

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• Unary NOT/Integersize of the architecture

  - by sid_com

  From "Mastering Perl/Chapter 16/Bit Operators/Unary NOT,~": The unary NOT operator (sometimes called the complement operator), ~, returns the bitwise negation, or 1's complement, of the value, based on integer size of the architecture Why does the following script output two different values? #!/usr/local/bin/perl use warnings; use 5.012; use Config; my $int_size = $Config{intsize} * 8; my $value = 0b1111_1111; my $complement = ~ $value; say length sprintf "%${int_size}b", $value; say length sprintf "%${int_size}b", $complement; Output: 32 64

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• LINQ to Entity, using a SQL LIKE operator

  - by Mario

  I have a LINQ to ENTITY query that pulls from a table, but I need to be able to create a "fuzzy" type search. So I need to add a where clause that searches by lastname IF they add the criteria in the search box (Textbox, CAN be blank --- in which case it pulls EVERYTHING). Here is what I have so far: var query = from mem in context.Member orderby mem.LastName, mem.FirstName select new { FirstName = mem.FirstName, LastName = mem.LastName, }; That will pull everything out of the Member table that is in the Entity object. Then I have an addition to the logic: sLastName = formCollection["FuzzyLastName"].ToString(); if (!String.IsNullOrEmpty(sLastName)) query = query.Where(ln => ln.LastName.Contains(sLastName)); The problem is when the search button is pressed, nothing is returned (0 results). I have run the query against the SQL Server that I expect to happen here and it returns 6 results. This is the query I expect: SELECT mem.LastName, mem.FirstName FROM Members mem WHERE mem.LastName = 'xxx' (when xxx is entered into the textbox) Anyone see anything wrong with this?

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• Javascript || or operator with a undefinded variable

  - by bryan sammon

  I have been doing some reading lately one article I read was from Opera. http://dev.opera.com/articles/view/javascript-best-practices/ In that article they write this: Another common situation in JavaScript is providing a preset value for a variable if it is not defined, like so: if(v){ var x = v; } else { var x = 10; } The shortcut notation for this is the double pipe character: var x = v || 10; For some reason I cant get this to work for me. Is it really possible to check to see if v is defined, if not x = 10? --Thanks. Bryan

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• index help for a MySQL query using greater-than operator and ORDER BY

  - by Jaymon

  I have a table with at least a couple million rows and a schema of all integers that looks roughly like this: start stop first_user_id second_user_id The rows get pulled using the following queries: SELECT * FROM tbl_name WHERE stop >= M AND first_user_id=N AND second_user_id=N ORDER BY start ASC SELECT * FROM tbl_name WHERE stop >= M AND first_user_id=N ORDER BY start ASC I cannot figure out the best indexes to speed up these queries. The problem seems to be the ORDER BY because when I take that out the queries are fast. I've tried all different types of indexes using the standard index format: ALTER TABLE tbl_name ADD INDEX index_name (index_col_1,index_col_2,...) And none of them seem to speed up the queries. Does anyone have any idea what index would work? Also, should I be trying a different type of index? I can't guarantee the uniqueness of each row so I've avoided UNIQUE indexes. Any guidance/help would be appreciated. Thanks!

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• DataTable.Select Behaves Strangely Using ISNULL Operator on NULL DateTime Column

  - by Paul Williams

  I have a DataTable with a DateTime column, "DateCol", that can be DBNull. The DataTable has one row in it with a NULL value in this column. I am trying to query rows that have either DBNull value in this column or a date that is greater than today's date. Today's date is 5/11/2010. I built a query to select the rows I want, but it did not work as expected. The query was: string query = "ISNULL(DateCol, '" + DateTime.MaxValue + "'") > "' + DateTime.Today "'" This results in the following query: "ISNULL(DateCol, '12/31/9999 11:59:59 PM') > '5/11/2010'" When I run this query, I get no results. It took me a while to figure out why. What follows is my investigation in the Visual Studio immediate window: > dt.Rows.Count 1 > dt.Rows[0]["DateCol"] {} > dt.Rows[0]["DateCol"] == DBNull.Value true > dt.Select("ISNULL(DateCol,'12/31/9999 11:59:59 PM') > '5/11/2010'").Length 0 <-- I expected 1 Trial and error showed a difference in the date checks at the following boundary: > dt.Select("ISNULL(DateCol, '12/31/9999 11:59:59 PM') > '2/1/2000'").Length 0 > dt.Select("ISNULL(DateCol, '12/31/9999 11:59:59 PM') > '1/31/2000'").Length 1 <-- this was the expected answer The query works fine if I wrap the DateTime field in # instead of quotes. > dt.Select("ISNULL(DateCol, #12/31/9999#) > #5/11/2010#").Length 1 My machine's regional settings is currently set to EN-US, and the short date format is M/d/yyyy. Why did the original query return the wrong results? Why would it work fine if the date was compared against 1/31/2000 but not against 2/1/2000?

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• bitwise not operator .

  - by Tony

  Why bitwise operation (~0); prints -1 ? In binary , not 0 should be 1 . why ?

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• Regex not operator

  - by Erik Goens

  I need to use a regex to pull a value out a url domain that will exclude everything but the host (ex: wordpress) and domain type (ex .com). The urls are dynamic and contain 2-3 values for each result (www.example.com or example.org). I am trying to use this expression, but I am only getting back the first letter of every item I am attempting to exclude: Expresssion (?!wordpress|com|www)(\w+|\d+) String example.wordpress.com Results example ordpress om Desired Result example Any assistance would be greatly appreciated

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• Cocoa @sum array operator too slow - alternatives?

  - by icodestuff

  I've got a text field value bound to a key path that uses @sum. When the array controller is filtered, the text field updates properly, but extremely slowly, lagging the UI or outright beachballing after every key press (less so as the number of items in arrangedObjects decreases). There is no lag if I don't use @sum; I've narrowed it down to this. Is there a faster way to do the same thing?

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• Microsoft SQL 2005 - using the modulo operator

  - by cc0

  So I have a silly problem, I have not used much MSSQL before, or any SQL for that matter. I basically have a minor mathematical problem that I need solved, and I thought modulo would be good. I have a number of dates in the database, but I need them be rounded off to the closest [dynamic integer] (could be anything from 0 to 5000000) which will be input as a parameter each time this query is called. So I thought I'd use modulo to find the remainder, then subtract that remainder from the date. If there is a better way, or an integrated function, please let me know! What would be the syntax for that? I've tried a lot of things, but I keep getting error messages like integers/floats/decimals can't be used with the modulo operators. I tried casting to all kinds of numeric datatypes. Any help would be appreciated.

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• How does the bitwise complement (~) operator work?

  - by bala

  Why is it that ~2 is -3?

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• Javascript comma operator

  - by Claudiu

  When combining assignment with comma (something that you shouldn't do, probably), how does javascript determine which value is assigned? Consider these two snippets: function nl(x) { document.write(x + "<br>"); } var i = 0; nl(i+=1, i+=1, i+=1, i+=1); nl(i); And: function nl(x) { document.write(x + "<br>"); } var i = 0; nl((i+=1, i+=1, i+=1, i+=1)); nl(i); The first outputs 1 4 while the second outputs 4 4 What are the parentheses doing here?

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• PHP Scope Resolution Operator Question

  - by anthony

  I'm having trouble with the MyClass::function(); style of calling methods and can't figure out why. Here's an example (I'm using Kohana framework btw): class Test_Core { public $var1 = "lots of testing"; public function output() { $print_out = $this->var1; echo $print_out; } } I try to use the following to call it, but it returns $var1 as undefined: Test::output() However, this works fine: $test = new Test(); $test->output(); I generally use this style of calling objects as opposed to the "new Class" style, but I can't figure out why it doesn't want to work.

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• How to use ternary operator instead of if-else in PHP

  - by Mac Taylor

  hey guys i need to shorten or better to say ., harden my codes this is my original code : if ($type = "recent") { $OrderType = "sid DESC"; }elseif ($type = "pop"){ $OrderType = "counter DESC"; }else { $OrderType = "RAND()"; } now how can i use markers like this : $OrderType = ($type = "recent") ? "sid DESC" : "counter DESC" ; i tried but i didnt know how to write elseif in operators

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• Microsoft SQL Server 2005 - using the modulo operator

  - by cc0

  So I have a silly problem, I have not used much SQL Server before, or any SQL for that matter. I basically have a minor mathematical problem that I need solved, and I thought modulo would be good. I have a number of dates in the database, but I need them be rounded off to the closest [dynamic integer] (could be anything from 0 to 5000000) which will be input as a parameter each time this query is called. So I thought I'd use modulo to find the remainder, then subtract that remainder from the date. If there is a better way, or an integrated function, please let me know! What would be the syntax for that? I've tried a lot of things, but I keep getting error messages like integers/floats/decimals can't be used with the modulo operators. I tried casting to all kinds of numeric datatypes. Any help would be appreciated.

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• R equivalent of .first or .last sas operator

  - by Giorgio Spedicato

  Does anybody know what is the best R alternative to SAS first. or last. operators? I did find none. SAS has the FIRST. and LAST. automatic variables, which identify the first and last record amongst a group with the same value with a particular variable; so in the following dataset FIRST.model and LAST.model are defined: Model,SaleID,First.Model,Last.Model Explorer,1,1,0 Explorer,2,0,0 Explorer,3,0,0 Explorer,4,0,1 Civic,5,1,0 Civic,6,0,0 Civic,7,0,1

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• Reverse ?? operator

  - by HeavyWave

  Is it possible to do something like this in C#? logger != null ? logger.Log(message) : ; // do nothing if null or logger !?? logger.Log(message); // do only if not null

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• STL: writing "where" operator for a vector.

  - by Arman

  Hello, I need to find the indexes in the vector based on several boolean predicates. ex: vector<float> v; vector<int> idx; idx=where( bool_func1(v), bool_func2(v), ... ); What is the way to declare **where** function, in order to use the several user defined boolean functions over the vector? thanks Arman.

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• sql-access: HAVING clause and != operator

  - by every_answer_gets_a_point

  i am new to access sql and i built a select statement that looks like this: SELECT [Lab Occurrence Form].[Practice Code], Count([Lab Occurrence Form].[1 0 Preanalytical (Before Testing)]) AS [CountOf1 0 Preanalytical (Before Testing)], [Lab Occurrence Form].[1 0 Preanalytical (Before Testing)] FROM [Lab Occurrence Form] WHERE ((([Lab Occurrence Form].[Occurrence Date]) Between #9/1/2009# And #9/30/2009#)) having ([CountOf1 0 Preanalytical (Before Testing)] != 0) GROUP BY [Lab Occurrence Form].[Practice Code], [Lab Occurrence Form].[1 0 Preanalytical (Before Testing)]; its not liking my HAVING clause. what is wrong with it? how do i do a != ??

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