Javascript to jumble up input box value

Question

Ok, I am writing some code which someone can use as a bookmarklet to jumble up an input box value in real time...

var elements = document.getElementsByTagName("input");
for (var ii = 0; ii < elements.length; ii++) {

    elements[ii].addEventListener("keyup", function() {

        var input = elements[ii].value;
        var a = [""];
        var gen;
        for (x in input) {
            a[x] = input[input.length - x - 1];
        };
        for (x in a) {
            var gen = gen + a[x];
        };
        output = gen.replace('undefined', '');
        elements[ii].value = output;
    }, false);
};

This code (with JavaScript: in front) doesn't have affect on any input boxes. Can anyone see why?

Thanks!

@raghavv no, it's supposed to jumble it up as the user is typing in. My problem was that there was no effect on the text. But it's fixed now. — InfiniDaZa, Dec 15 '12 at 18:41

score 1 · Answer 1 · answered Dec 15 '12 at 17:20

1

Use this instead of elements[ii] inside the addEventListener code. Cos elements[ii] will have no meaning inside that code.

answered Dec 15 '12 at 17:20

LPD

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Hmmm still doesn't work. I'll keep looking around. Thanks anyway! – InfiniDaZa Dec 15 '12 at 17:23

score 1 · Accepted Answer · answered Dec 15 '12 at 17:29

1

I did a few fixes in your code. Here is the modified version:

var elements = document.getElementsByTagName("input");
for (var ii = 0; ii < elements.length; ii++) {

    elements[ii].addEventListener("keyup", function() {

        var input = this.value;
        var a = [];
        var gen;
        for (var x in input) {
            a[x] = input[input.length - x - 1];
        };
        for (x in a) {
            var gen = gen + a[x];
        };
        output = gen.replace('undefined', '');
        this.value = output;
    }, false);
};

please check demo

answered Dec 15 '12 at 17:29

closure

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Now that I look at this again, other than the `undefined`, isn't all of this the same as `this.value = this.value.split('').reverse().join('');` – Paul S. Dec 15 '12 at 18:54
Yes, this is how you would reverse it. That was my first question. Your reverse logic is perfect. Besides, there is no need of 'undefined' check. There is nothing 'undefined' I have seen. – closure Dec 15 '12 at 19:32
If you saw no `undefined` when why did you do `output = gen.replace('undefined', '');`? This is because the _for..in_ is unfiltered; it includes all the enumerable properties on the object and it's prototype chain. – Paul S. Dec 15 '12 at 21:11

Javascript to jumble up input box value

2 Answers2