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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...
Started by Youval Bronicki on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
I never....
The common check for undefined is therefore done like this:
typeof x == "undefined"
this ensures the type of the variable is really undefined.
The problem is that undefined compared to null using == gives true.
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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;...
Started by Claudiu on
, 8 posts
by 8 people.
Answer Snippets (Read the full thread at stackoverflow):
Something like this?
function isDefined(var....
Prop); if (o.x === undefined && contains(prop, 'x')) { //x is defined, but set to undefined }
where putting a watch on One.x but that would only tell you at the time it gets undefined.
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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.
Started by Matt Sheppard on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
If (somevariable == undefined) { alert('the variable is not defined!'); }
You can also make it into a function, as shown here :
function isset(varname){ return(typeof(window[varname]) != 'undefined'); }
In JavaScript there is null and there....
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Ask your Facebook Friends
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So I have been through most of the questions here. Also quite a few articles good and bad.
One thing I am looking for some additional clarification on is how undefined and un declared variables are treated.
Take the code below.
var a; if(a == null) //...
Started by Knife-Action-Jesus on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
So when you do need to test, I would write it something like this:
if( typeof(a) != '....
I have to navigate through object where any of the parents could be undefined .
I can immediately assume c is undefined if a is undefined?
Yes.
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How to resolve undefined references [linker error] in dev cpp?
Started by mark on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
If you're linking to a library, such as the math library libmath, be sure to link to the library in your makefile/compilation... .
Sounds like you aren't linking up all required object files and libraries .
You look at where the error is and fix your typo .
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When I nm on one of my libs:
nm libmylib.so
I get a line like this
U _ZNSs4_Rep20_S_empty_rep_storageE@@GLIBCXX_3.4
I checked the man page for nm and I got "U" The symbol is undefined. What does an undefined symbol really mean?
If it is really undefined...
Started by bbazso on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Alternatively the symbol is undefined because you've library so you would expect that to be undefined....
An undefined symbol is a symbol that the library uses but was not defined in any of the object needs to be linked in to your application.
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Turns out many innocently looking things are undefined behavior in C++. For example, once a non-null pointer has been delete 'd even printing out that pointer value is undefined behavior .
Now memory leaks are definitely bad. But what class situation ...
Started by sharptooth on
, 12 posts
by 12 people.
Answer Snippets (Read the full thread at stackoverflow):
There is....
Memory leaks.
Undefined behavior crash will occur.
Expand that repertoire of behaviors so you can call it by its proper name: a bug .
Memory leaks are definitely defined in C/C++.
Can probably cause undefined behaviour later.
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If you attempt to use a variable that does not exist and has not been declared, javascript will throw an error. var name is not defined , and the script will stop then and there.
But if you check it using typeof noname then it will return "undefined" ...
Started by Tobos on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Undefined is the difference between var a; and var b = undefined;
var a; alert(a); // undefined a; alert(a); // "Error "a" not defined" a = ....
I believe it's a difference between JavaScript definition and firebugs of the same thing .
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I've been getting this undefined symbol building with this command line:
$ gcc test.cpp Undefined symbols: "___gxx_personality_v0", referenced from: etc...
test.cpp is simple and should build fine. What is the deal?
Started by ryan_s on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
According to this page the extension does matter: http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc....
The extension .cpp causes gcc to compile your file as a c++ file .
:)
Use
g++ test.cpp
instead, since this is c++ code.
The deal is that you're tired and dumb.
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How to turn of displaying this error in wamp: notice undefined offset Turn of only error like that, not all errors-
tnx
Started by Wizard4U on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
E_NOTICE
Run-time....
Then you are on the save side.
Set the error reporting to
error_reporting(E_ERROR | E_WARNING | E_PARSE)
But better would be to actually check what is the cause of the Notice and fix it .
You could e.g.
Have a look at error_reporting().
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