shuyar-util/lib/random.js

Some useful function or tools in development.

;(function () {
    
    /**
     * Created by Galen Sheen
     * @Desc 生成随机字符串
     */
    
    // Reference to the global object
    var root = this;
    
    // Numerics
    var nums = [
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
    ];
    
    // Lower case letters
    var lowers = [
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
    ];
    
    // Upper case letters
    var uppers = [
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
    ];
    
    // Symbols
    var symbols = [
        '!', '$', '@', '#', '%', '^', '&', '*'
    ];
    
    function randomIndex(n) {
        return Math.floor(Math.random() * n);
    }
    
    // The main function to generate random string according the length and array of charaters
    function randomGen (n, chars) {
        
        n || (n = 8);
        
        var str = '';
        
        for (var i = 0, len = chars.length; i < n; i++) {
            str += chars[randomIndex(len)];
        }
        
        return str;
    }
    
    // Main random method
    var random = {
        number: function (n) {
            return randomGen(n, nums);
        },
        lower: function (n) {
            return randomGen(n, lowers);
        },
        upper: function (n) {
            return randomGen(n, uppers);
        },
        letter: function (n) {
            var arr = lowers.concat(uppers);
            return randomGen(n, arr);  
        },
        alpha: function (n) {
            var arr = lowers.concat(uppers).concat(nums);
            return randomGen(n, arr);
        },
        any: function (n) {
            var arr = lowers.concat(uppers).concat(nums).concat(symbols);
            return randomGen(n, arr);
        }
    }
    
    // Exports, check the env, node or browser
    if (typeof module !== 'undefined' && module.exports) {
        // Node env
        module.exports = random;
    } else if (typeof window !== 'undefined') {
        // Browser env
        root.random = random;
    } else {
        return random;
    }
}).call(this);