What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?...
Why does the following work? <something>.stop().animate( { 'top' : 10 }, 10 ); Whereas this doesn't work: var thetop = 'top'; <something>.stop().animate( { thetop : 10 }, 10 ); To make it even clearer:...I know it's possible in PHP to have "variable" variables. For example $x = "variable"; $$x = "hello, world!"; echo $variable; // displays "hello, world!" Is it possible to refer to a variable by its name as a...
Given this snippet of JavaScript... var a; var b = null; var c = undefined; var d = 4; var e = 'five'; var f = a || b || c || d || e; alert(f); // 4 Can someone please explain to me what this technique is called (my best guess is in th...
Which method of checking if a variable has been initialized is better/correct? (Assuming the variable could hold anything (string, int, object, function, etc.)) if (elem) { // or !elem or if (typeof(elem) !== 'undefined') { or if (el...I know in PHP we can do something like this: $hello = "foo"; $my_string = "I pity the $hello"; Output: "I pity the foo" I was wondering if this same thing is possible in JavaScript as well. Using variables inside strings...
So for example: function(input){ var testVar = input; string = ... string.replace(/ReGeX + testVar + ReGeX/, "replacement") } But this is of course not working :) Is there any way to do this?...I wanted to check whether the variable is defined or not. For example, the following throws a not-defined error alert( x ); How can I catch this error?...
What are the differences and/or advantages, if any, of using commas when declaring a group of variables rather than semicolons. For example: var foo = 'bar', bar = 'foo'; versus var foo = 'bar'; var bar = 'foo';...
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