JavaScript 代码 优化笔记

1. 判断某个元素是否在数组中。

    setCheckNodes : function (zNodes, checkIds){
        var that = this;
        that.setAllNodesUnchecked(zNodes);
        $.each(checkIds, function(codeIndex, code){
            $.each(zNodes, function (nodeIndex, node) {
                if(node.code==code){                               //for很慢
                    node.checked = true;
                }
                if(node.children){
                    that.setCheckNodes(node.children, checkIds);
                }
            });
 
        });
 
        return zNodes;
    },

indexOf 很快

    setCheckNodes : function (zNodes, checkIds){
        var that = this;
        that.setAllNodesUnchecked(zNodes);
        $.each(zNodes, function (nodeIndex, node) {
            if(checkIds.indexOf(node.code) !== -1){
                node.checked = true;
            }
            if(node.children){
                that.setCheckNodes(node.children, checkIds);
            }
        });
        return zNodes;
    },