JavaScript Memoization

Snippets

/**
 * JavaScript Momoization
 * @param {string} func name of function / method
 * @param {object} [obj] mothed's object or scope correction object
 *
 * MIT / BSD license
 */

function Memoize(func, obj){
    var obj = obj || window,
        func = obj[func],
        cache = {};
    return function(){
        var key = Array.prototype.join.call(arguments, '_');
        if (!(key in cache))
            cache[key] = func.apply(obj, arguments);
        return cache[key];
    }
}

var fib = {
    fib: function(n){
         if (n == 0 || n == 1)
             return 1;
        return this.fib(n-1) + this.fib(n-2);
    },
    fib_memo: function(n){
         if (n == 0 || n == 1)
             return 1;
        return this.fib_memo(n-1) + this.fib_memo(n-2);
    }
}

fib.fib_memo = Memoize('fib_memo', fib);

测试 fib.fib(30)

测试 fib.fib_memo(30)