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Archive for May, 2013

Test if the given value is a decimal number or not in JavaScript using Regular Expression

26 May

To identify in JavaScript whether the number or a string is in a decimal format or not, is actually pretty easy and short.
It looks obvious, but actually it doesn’t due to several different combinations of decimal number representation in JavaScript.

I’m using Regular Expression to test it:

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function isDecimal(number) {
    return /^\d+(\.\d+|e)(e?-\d+)?$/.test(number);
}

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The efficient way to create GUID/UUID in JavaScript (with explanation)

22 May

I want to share with you the fastest GUID/UUID generator method (as far as I know).

Million executions of this implementation takes just 32.5 seconds, which is the fastest i’ve ever seen in a browser (the only solution without loops/iterations).

The function is as simple as:

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/**
 * Generates a GUID string.
 * @returns {String} The generated GUID.
 * @example af8a8416-6e18-a307-bd9c-f2c947bbb3aa
 * @author Slavik Meltser ([email protected]).
 * @link http://slavik.meltser.info/?p=142
 */

function guid() {
    function _p8(s) {
        var p = (Math.random().toString(16)+"000000000").substr(2,8);
        return s ? "-" + p.substr(0,4) + "-" + p.substr(4,4) : p ;
    }
    return _p8() + _p8(true) + _p8(true) + _p8();
}

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