What's the best way of checking if an object property in JavaScript is undefined? Sorry, I initially said variable rather than object property. I believe the same == undefined approach doesn't work there. ...
I have inherited some code for a custom CMS that is a little out of my league and keep stumbling over the same errors, Notice: Undefined variable: media in /Applications/MAMP/htdocs/Chapman/Chapman_cms/admin/team-2.php on line 48. This is supposed to create new users and edit old users. However, it does not work when I try and add a new ...
I'm trying to link a Qt application with its libraries and the linker (MinGW) spews hundreds of lines like the following, and I am unsure how to proceed. cpp: undefined reference to `_Unwind_SjLj_Register' c:/qt/lib/libQtCore.a(qcoreapplication_win.o)(.text+0x29d):qcoreapplication_win. cpp: undefined reference to `_Unwind_SjLj_Unreg...
Say like a[i] = i++; ...
The same as this question but for java Update Based on the comments and responses of a few people, Its clear that Java has very little undefined behaviour. So I'd like to ask as well what behaviour is not obvious. Please when answering make the disticnction between the two :) ...
I'm just wondering if there is a quick way to echo undefined variables without getting a warning? (I can change error reporting level but I don't want to.) The smallest I have so far is: isset($variable)?$variable:'' I dislike this for a few reasons: It's a bit "wordy" and complex $variable is repeated The echoing of a blank string a...
Say I have the following code: function One() {} One.prototype.x = undefined; function Two() {} var o = new One(); var t = new Two(); o.x and t.x will both evaluate to undefined. o.hasOwnProperty('x') and t.hasOwnProperty('x') will both return false; the same goes for propertyIsEnumerable. Two questions: Is there any way to tell t...
In JavaScript, there are two values which basically say 'I don't exist' - undefined and null. A property to which a programmer has not assigned anything will be undefined, but in order for a property to become null, null must be explicitly assigned to it. I once thought that there was a need for null because undefined is a primitive va...
I'm having several "undefined reference" (during linkage) and "unresolved symbol" (during runtime after dlopen) issues where I work. It is quite a large makefile system. Are there general rules and guidelines for linking libraries and using compiler flags/options to evade these types of errors? ...
How to check whether a JavaScript variable defined in cross-browser way? I ran into this problem when writing some JavaScript utilizing FireBug logging. I wrote some code like below: function profileRun(f) { // f: functions to be profiled console.profile(f.constructor); f(); console.profileEnd(f.constructor); } It wor...
I have this code here: var infiltrationResult; while(thisOption) { var trNode = document.createElement('tr'); var tdNode = document.createElement('td'); var hrefNode = document.createElement('a'); infPlanetID = thisOption.getAttribute('value'); var myURL = "http://www.hyperiums.com/servlet/Planetinf?securitylevel=90...
Is there any tool that will help detect potential errors like "undefined function" in a PHP script before runtime? For example, consider: <?php zarfnutz ( 'blah' ); ?> If you ask the PHP command line interface to check that for syntax errors, it responds that there are none. But of course the script will fail if you try to run it, b...
I used a backslash to continue a Ruby statement on the next line. print abc \ + def I added a space after the backslash, because I like to blow things up, and, sure enough, I got an error: unexpected $undefined, expecting $end I assume $undefined is a global variable that means anything the compiler sees that it doesn't recognize -...
I can't seem to make this undefined reference go away. http://imgur.com/1qqDi.png (screenshot of issue) I have this code under the private section of Scene.h: static Scene * scene_; There is a #include "Scene.h" at the very first part of the header of Scene.cpp This is the only error I'm receiving at the moment, any ideas? I'll s...
When I recently integrated Facebook Connect with Tersus, I initially received the error messages Invalid Enumeration Value and Handler already exists when trying to call Facebook API functions. It turned out that the cause of the problem was object.x === undefined returning false when there is no property 'x' in 'object'. I worked a...
I've tried looking at similar problems, but could not easily find one that helped my problem. I've created a project in C++ and am working on UNIX to compile, link, and run it. My specific problem is an undefined reference to a method I declare in a separate file. In the file SharedCache.cpp, I have the following method: int SharedCac...
I wanted to check whether the variable is defined or not. eg alert( x ); Throws a not defined error How can I catch this error? ...
Fatal error: Call to undefined function lcfirst() in C:\xampp\htdocs\allsides\others\basecontroller.php on line 9 How come it didn't find a Text Proccessing function mentioned in the official php manual (http://www.php.net/manual/en/function.lcfirst.php)? ...
I've been having big problems in reproducing and finding the cause of a bug. The occurence seems entirely random, so I suspected an uninitialized variable somewhere. But then I found this piece of code: CMyClass obj; // A obj.DoStuff(); if ( somebool ) { CMyClass obj; // B obj.DoStuff(); } obj.DoOtherStuff(); It seems as tho...
A simple Bash variable test goes: ${varName:? "${varName} is not defined"} I'd like to re-use this, by putting it in a function. How please? Following fails # # Test a variable exists tvar(){ val=${1:? "${1} must be defined, preferably in $basedir"} if [ -z ${val} ] then echo Zero length value else echo...