Why I get TypeError creating jQuery plugin after modifying String.prototype

Question

Try to create a jQuery plugin after you've modified String.prototype, and you get a TypeError. Why? Is it a jQuery's bug? It does bother me when it comes to function ordering. Now I have to always take care of creating jQuery plugins before modifying prototypes. See these fiddles:

This fiddle Throws Type Error (because jQuery plugin is created after prototype modification)

This fiddle is ok.

Semicolons are rarely "important" in JS. They just happen to be in this exact situation where the next line of code is wrapped in (), causing this problem. There aren't many other "important" situations, but it includes the format of return statements. — Ian, Jul 11 '12 at 08:28

score 4 · Answer 1 · answered Jul 11 '12 at 08:23

4

String.prototype.digitGroup = function () {
    // Code here
    return;
}; // Add a semicolon here to avoid error

(function ($) {
    $.fn.showDialog = function (options) {
        // Code here
        return this;
    };
})($);

answered Jul 11 '12 at 08:23

Andrew D.

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score 3 · Accepted Answer · edited May 23 '17 at 12:25

3

Just put a semicolon after this function expressin

String.prototype.digitGroup = function () {
    // Code here
    return;
}; // Here

Updated fiddle.

Semicolons are optional in javascript but some times it matters so you should always use semicolon, it's a good programming practice, check this and also this on SO.

edited May 23 '17 at 12:25

Community

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answered Jul 11 '12 at 08:22

The Alpha

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How strange it was. I never thought of that little little `;` to be the root of the problem. Thanks. – Saeed Neamati Jul 11 '12 at 09:06

Why I get TypeError creating jQuery plugin after modifying String.prototype

2 Answers2