How to convert a string value to a variable in javascript?

Question

var test1;
$(document).ready(function () {
    test1 = $("#test1ID").jQueryPlugin();
});

var test2;
$(document).ready(function () {
    test2 = $("#test2ID").jQueryPlugin();
});

...

This is done so we could just do test1.foo()... foo is a function inside the jQueryPlugin that is accessible using test1.foo() syntax;

So we have an array of strings which contains (test1, test2, ...) and we need to access foo() while on the loop:

for(i=0; i < theArrayOfStrings.length; i++){
    theArrayOfStrings[i].foo();
    //so here is the problem... we can't do test1.foo(), test2.foo() ... =(
}

Any idea on how to call function foo() while on the loop? Or can we convert a string value to a variable in javascript?

Answer 1

Have you tried

$('#' + theArrayOfStrings[i]).foo();

Have a look at API/1.3/Selectors

Answer 2

eval() function is used to evaluate script in a string variable. For example :

var test1;
eval("test1=" + theArrayOfStrings[i]);
test1.foo();

But take a lok at this question before use When is JavaScript’s eval() not evil?

Answer 3

var test = [], n = 5;
$(document).ready(function () {
    for(var i=0; i < n; i++)
        test.push($("#test"+i+"ID").jQueryPlugin());
});

// the values in test won't be accessible before the document is loaded.

Answer 4

It might be worth creating an object to hold all your "tests":

var tests = {};

$(document).ready(function () {
    tests.test1 = $("#test1ID").jQueryPlugin();
    tests.test2 = $("#test2ID").jQueryPlugin();
});

for(i=0; i < theArrayOfStrings.length; i++){
    tests[theArrayOfStrings[i]].foo();
}

Answer 5

If test1 is a global variable you can access it by name through the window object:

window[theArrayOfStrings[0]].foo();   // test1();

If it's not, eval is the only way, but I'd strongly advise avoiding eval in all circumstances. Using a lookup as in J-P's answer (+1) is much much more appropriate than selecting variable names.