I need to assign a variable name from a second variable, then alert the value of the first variable in JavaScript.
Below is an example of what I am trying to achieve.
window.foo=0;
window.bar="window.foo";
//want to set an alert for window.bar in a way that returns 0
alert(window.bar); //returns window.foo
alert(Number(window.bar)); //returns window.NaN
In the example above, I am looking to alert the value 0. How would that be accomplished? Thank you.
If they're global variables (as those are), you can simply use "foo" rather than "window.foo" when looking it up on window:
var name = "foo";
window.foo = 0;
alert(Number(window[name])); // 0;
But global variables are a Bad Thing(tm).
To do this without globals, use your own object:
var name = "foo";
var obj = {};
obj.foo = 0;
alert(Number(obj[name])); // 0;
Both of the above work because in JavaScript, you can refer to an object property either with dot notation and a literal (obj.foo), or with bracketed notation and a string (obj["foo"]), and in the latter case, the string can be the result of any expression, including a variable lookup.
eval function: alert(Number(eval(window.bar)));
