undefined

Is there a way to handle undefined functions being called in JavaScript?

If I have a function like the following: function catchUndefinedFunctionCall( name, arguments ) { alert( name + ' is not defined' ); } and I do something silly like foo( 'bar' ); when foo isn't defined, is there some way I can have my catch function called, with name being 'foo' and arguments being an array containing 'bar'? ...

var undefined = true;

I'm doing some experimenting with this malicious JavaScript line: var undefined = true; Every uninitialized variable in JavaScript has the value of undefined which is just a variable that holds the special value of 'undefined', so the following should execute the alert: var undefined = true, x; if (x) { alert('ok'); } But i...

Undefined vs window.undefined in JavaScript

Can someone explain way this work if(window.a){} while this is failing if(a) In both cases a is undefined. ...

How to check for undefined or null variable in javascript

We are frequently using the following code pattern in our javascript code if(typeof(some_variable) != 'undefined' && some_variable != null) { // do something with some_variable } and I'm wondering whether there is a less verbose way of checking that has the same effect. According to some forums and literature saying simply if(s...

Old functions return 'undefined' error once I add a jquery reference

Disregard this question: I've simply confused <script src="..."></script> tag and <script> [some functions] </scipt> tags. I have this function function OnLoad() { ShowHideConfirmAnswers(); return true; } triggered by onload event: <body onload=OnLoad()> It works fine until I add src="jquery-1.4.2.js" to the script elemen...

What's causing "NoMethodError: undefined method `include?' for nil:NilClass"

I have a Book model in my Rails application, with various properties (aka columns in the book db table). One of these properties is "ranking". Recently, may app has started to throw NoMethodError: undefined method 'include?' for nil:NilClass for the following code: def some_method(book, another_arg) return book.ranking unless book.ra...

How to determine if variable is 'undefined' or 'null'

How do I determine if variable is 'undefined' or 'null'. My code is as follows: EmpName = $("div#esd-names div#name").attr('class'); if(EmpName == 'undefined'){ ///DO SOMETHING///// }; ...

Javascript array value is undefined ... how do I test for that

I am trying to test to see whether a Javascript variable is undefined. You will see that I am not expecting the value of predQuery[preId] to be 'undefined' if I don't first get an alert saying "its unbelievable". But I often do, so I am guessing that my statement predQuery[preId]=='undefined') is not matching the undefined elements...

Check if an object is defined in html

In HTML, I have an object tag as follows: <OBJECT ID="objectid" CLASSID="some-class-id" CODEBASE="some-codebase"> I have written a function in JavaScript to access this object. I checked the null value as follows: if(objectid==null){-----} i want to check if the object is undefined or is empty. Do we have any functions to check s...

AJAX call works on local machine, not on host

hey everyone, What could potentially stop an AJAX call from working on the host server, when it works fine on the local host? I tried returning an error from the AJAX call, but all I get is 'undefined'. I don't think the actual page method is being called since no information is added in my log (and I've explicitly added a call). I ca...

Variable is Undefined

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; <html xmlns="http://www.w3.org/1999/xhtml"&gt; <HEAD> <script type="text/javascript" src="lb-core.js"></script> <script type="application/javascript"> var lbp = { defaults: { color: "blue" }, in...

Javascript: previous property is undefined

Why is it saying that "lbp is undefined" on the line of "creditText"? How do I refer to previous properties in a config file such as this? var lbp = { // Pertinant page properties, such as Author, Keywords, URL or Title page: { theURL: window.location.toString(), }, // Configurable user defaults defaults: {...

undefined variable with $_GET??

Hello I have this problem in php: Notice: Undefined variable: _Get in /.../script/install.php on line 3 and this is the code in line 3: if($_Get['step']<1) so what is the problem? ...

undefined method ‘bytes’ for for String in Ruby

I am working with ruby 1.8.6 (2007-03-13 patchlevel 0) [x86_64-linux] and I get undefined method `bytes' for #<String:0x2a95ec2268> (NoMethodError) even though my code works on ruby 1.8.7. patchlevel 249 I saw somewhere that you need to add require "jcode" for a similar method not defined error with each_byte. I tried adding that but...

javascript undefined compare

Ok, here is my question: in javascript you can declare a variable and if it's undefined you can apply variable == undefined, I know that but how can you compare a value that you dont know yet if it's in the cpu memory. I have a class which is created when the user clicks a button. Before this the class is undefined, it doesn't exist anyw...

Why is Matlab Stateflow 7.7 not throwing errors on undefined variables?

Previously in Matlab Stateflow 7.1 all variables and functions had to be included before they can be referred to in the state diagram or else it would throw an error when you tried to parse the diagram. But now in 7.7 it doesn't catch those kinds of errors. Its still compiling the diagram because it catches other syntactic errors. Am ...

Needing forward declaration in Ruby

Hi, I am trying to write a Ruby script in one file. I would like to know if it is possible to write the "main" function in the beginning, having the other functions that are used by main, defined after it. In other words, I would like to call a not yet defined function, so that they do not depends on definition order. Just changing the...

Is there a config option in PHP to prevent undefined constants from being interpreted as strings?

This is from the php manual: http://us.php.net/manual/en/language.constants.syntax.php If you use an undefined constant, PHP assumes that you mean the name of the constant itself, just as if you called it as a string (CONSTANT vs "CONSTANT"). An error of level E_NOTICE will be issued when this happens. I really don't like this be...

Query with UDF works in Access but gives Undefined function in expression (Err 3085) in Excel

I have an Access table with a date/time field. I wanted to make a composite Key field out of the date/time field and 3 other text fields in the same format as the matching Key field in another database. So I concatenated the 3 text fields and wrote a User-Defined-Function in a Module to output the date field as a string in the format "Y...

Strange data behaviour, undefined variables etc.

Hi, My script works very strange, I get all the values, but when I want to check them by alerting them - first one gives "undefined", and other ones is correct. But if I don't make any alert all variables shows "undefined". My code: var arr = new Array(); function fetchData(){ $.get("post.php", function(data){ ...