在JavaScript中从头开始创建秒表

时间:2017-01-18 01:27:58

标签: javascript timer stopwatch

通过创建毫秒,秒和分钟的变量,我想制作一个小秒表项目。我所拥有按钮的onClick适用于theTimer()

var milli = 0;
    var seconds = 0;
    var minutes = 0;
    var onOff = 0;

    var txtMilli = document.getElementById("txtMilli");
    var txtSeconds = document.getElementById("txtSeconds");
    var txtMinutes = document.getElementById("txtMinutes");

    function theTimer()
    {
        if (onOff == 0) {
            onOff = 1;
            timer = setInterval("startCounting()",1);
        }
        if (onOff == 1) {
            onOff == 0;
            clearInterval(timer);
        }
    }

    function startCounting()
    {
        if (milli >999) 
        { 
          milli = 0; if (seconds <60) {seconds +=1} 
        }
        else 
        {
          milli +=1;
        }
        if (seconds >59) 
        {
          seconds = 0; minutes += 1;
        }
        if (milli > 10) 
        {
          txtMilli.innerHTML = "0" + milli;
        }
        if (milli < 10) 
        {
          txtMilli.innerHTML = "" + milli;
        }
    }

控制台中没有显示任何内容,问题是DIV在运行时永远不会从0更改。

1 个答案:

答案 0 :(得分:1)

我设法像这样修复你的代码:

var milli = 0;
var seconds = 0;
var minutes = 0;
var onOff = 0;

var txtMilli = document.getElementById("txtMilli");
var txtSeconds = document.getElementById("txtSeconds");
var txtMinutes = document.getElementById("txtMinutes");

function startCounting(){        
    if (milli >999) { milli = 0; if (seconds <60) {seconds +=1} }
    else {milli +=1;}
    if (seconds >59) {seconds = 0; minutes += 1;}

    if (milli > 10) {txtMilli.innerHTML = "0" + milli;}
    if (milli < 10) {txtMilli.innerHTML = "" + milli;}
}

function theTimer(){
    if (onOff == 0) {
        onOff = 1;
        timer = setInterval(startCounting, 1);
    } else if (onOff == 1) {
        onOff = 0;
        clearInterval(timer);
    }
}

myButton.onclick = theTimer;

theTimer中有一个错误,您将onOff设置为1,然后立即检查它是否为1并将其重新设置为{{} 1}}。我使用0修复此问题。

我还将else if(这是一个比较)更改为onOff == 0(这是一项作业)。

使用JSFiddle:https://jsfiddle.net/k83tvfhc/