一个javascript的问题

Question

function time(){
    var btn=window.document.getElementById("time");
        
        if(btn)
        {
        var now=new Date();
        var nowhours=now.getHours();
        var nowminutes=now.getMinutes();
        var nowseconds=now.getSeconds();
        if(nowseconds==59)
        {
            nowseconds=0;
            nowminutes++;
            if(nowminutes==59)
            {
                nowminutes=0;
                nowhours++;
                if(nowhours==23)
                {
                    nowhours=0;
                }
            }
        }
        else
        {
            nowseconds++;
        }
        btn.value=nowhours+":"+nowminutes+":"+nowseconds;
        }
    }
    setInterval("time()",1000);
它的运行结果比正常的要快一秒  我知道啥原因 但不知道如何解决 求解决

Answer 1

function time(){
var btn=window.document.getElementById("time");
btn.value = new Date().toLocaleTimeString();
}
setInterval("time()",1000);
这样就可以了

Answer 2

因为你调用time()的时候就是获取了本地时间，然后紧接着又对nowseconds++操作，所以时间肯定快了1秒
修改的话你只要把这句改成下面这样就可以了var nowseconds=now.getSeconds() - 1;

Answer 3

调了一下。你的程序有问题。比如13:40:40
nowseconds就会变成41，不知道你为什么要这样写。 function time() {
            var btn = window.document.getElementById("testButton");            if (btn) {
                var now = new Date();
                var nowhours = now.getHours();
                var nowminutes = now.getMinutes();
                var nowseconds = now.getSeconds();
//                if (nowseconds == 60) {
//                    nowseconds = 0;
//                    nowminutes++;
//                    if (nowminutes == 60) {
//                        nowminutes = 0;
//                        nowhours++;
//                        if (nowhours == 24) {
//                            nowhours = 0;
//                        }
//                    }
//                }
//                else {
//                    nowseconds++;
//                }
                btn.value = nowhours + ":" + nowminutes + ":" + nowseconds;
            }
        }
        setInterval("time()", 1000);