jquery 打字速度 变量问题？请教大侠！！

Question

var i=0;
$inp.bind("keypress", function (e){
                    var endDate;
                    var end;
                    if(i==0)
                    {
                        var startDate=new Date();
                        i=i+1;
                        var start =startDate.getTime()/1000;
                        alert (start);    
                    }
                    else
                    { 
                        endDate=new Date ();
                        end=endDate .getTime ()/1000;
                        i=i+1;
                        alert(end);
                        alert(start);        //总是输出undefined，这是为何？变量未定义？
                        var totaltime=Math.round(parseInt(end)-parseInt(start));
                        alert(totaltime.toString());
                        var speed=Math.round(i/totaltime*60);
//                        alert (speed );
                    
                        $("#lblInfoShow").text(''+speed +'');
这是我用来输出打字速度的，请大侠帮帮忙，小弟不胜感谢

Answer 1

你的start是在if中定义的,对else中的代码是无效的

Answer 2

var start =startDate.getTime()/1000;你可以把 var去掉 在一次测试

Answer 3

把Start定义到外面 不要放在if里面
var endDate;
var end;
var start;
...
...
var start =startDate.getTime()/1000; 这句话中把var去掉