JavaScript - string containing the name of a function

Question

Normally, if I had a string containing the name of a function, I could do something like ...

window[functionName](arguments);

However, that doesn't work when using "jQuery object" style programming (or whatever the correct term is). For example;

(function ($) {
    "use strict";
    $.test = (function () {
        var func1 = function () {
            alert("func1");
        };

        var func2 = function () {
            alert("func2");
        };

        return {
            Test: function (functionName) {
                var fn = window[functionName]; // Need to specify scope here, somehow
                if (typeof fn === 'function') {
                    fn();
                } else {
                    alert("fn() = " + fn);
                }
            }
        }

    } ());
} (jQuery));

$.test.Test("func1");
$.test.Test("func2");

Ideally this would display func1 followed by func2 - but clearly the scoping is wrong, and I'm not sure how to indicate it in this case.

How can I specify the scope of the function that I'm trying to call in this case? I could of course use eval(), but I'm trying to avoid that ...

Thanks.

@AndyE's answer is correct, but for your reference, this "jQuery object style" doesn't have an official term, but is an example of a closure (i.e., lexical scope) created using an immediately invoked function expression. — Xophmeister
– Xophmeister, Commented Mar 28, 2013 at 11:17

Andy E · Accepted Answer · 2013-03-28 11:06:38Z

4

Use an object map to house the functions instead:

    var funcs = {
        func1: function () {
            alert("func1");
        },
        func2: function () {
            alert("func2");
        }
    };

    return {
        Test: function (functionName) {
            var fn = funcs[functionName];
            if (typeof fn === 'function') {
                fn();
            } else {
                alert("fn() = " + fn);
            }
        }
    };

answered Mar 28, 2013 at 11:06

Andy E

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1 Comment

gdt Over a year ago

Thanks; kind of obvious in hindsight, but I was going down the wrong scoping alley!

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