JS 缓存

    /*
    js缓存类
    调用方法。
    var obj=new CacheHelper();
    obj.init();
    obj.addCache(1,"a");
    obj.addCache(2,"b");
    obj.addCache(3,"c");
    obj.addCache(4,"d");
    obj.addCache(5,"e");
    alert(obj.getCacheByKey(3))
    */
    function CacheHelper() {
        this.cache = new Array();
    }

    CacheHelper.prototype = {
        init: function () {
            this.cache = null;
            this.cache = new Array(); ;
        },
        //判断缓存是否存在
        isExist: function (id) {
            for (var i = 0; i < this.cache.length; i++) {
                if (this.cache[i].id == id)
                    return true;
            }
            return false;
        },
        //添加缓存
        addCache: function (id, value) {
            if (!this.isExist(id)) {
                var obj = { id: id, value: value };
                this.cache.push(obj);
            }
        },
        //取得缓存大小
        getCacheSize: function () {
            return this.cache.length;
        },
        //根据缓存键值取得缓存值
        getCacheByKey: function (id) {
            for (var i = 0; i < this.cache.length; i++) {
                if (this.cache[i].id == id)
                    return this.cache[i].value;
            }
            return "";
        }

    }