测试脚本运行时间

// 测试脚本运行时间
var Timer = {
_data : {},

start : function(key){
Timer._data[key] = new Date();
},

stop : function(key){
var time = Timer._data[key];
if(time){
Timer._data[key] = new Date() - time;
}
},

getTime : function(key){
return Timer._data[key];
}
};

var count = 10000, i,element;

Timer.start('createElement');
for(i = 0; i < count; i++){
element = document.createElement("div");
}

Timer.stop('createElement');
console.log('create' + count + 'in' + Timer.getTime('createElement'));