js实现计算器和计时器功能
本文实例为大家分享了js实现计算器和计时器的具体代码，供大家参考，具体内容如下
完成简单的计算器
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
#box {
width: 250px;
height: 200px;
background-color: #C0C0C0;
}
input{
width: 50px;
height: 27px;
}
#text{
width: 229px;
}
</style>
<script type="text/javascript">
var num = 0;
function str(num) {
document.getElementById('text').value += document.getElementById(num).value;
}
function eva() {
var res = eval(document.getElementById("text").value);
document.getElementById("text").value = res;
}
function clearNum() {
document.getElementById("text").value = null;
}
</script>
</head>
<body>
<div id="box">
<table cellspacing="0" cellpadding="5px">
<tr>
<th colspan="4">
<input type="text" id="text" />
</th>
</tr>
<tr>
<th>
<input type="button" value="7" id="7" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="8" id="8" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="9" id="9" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="+" id="+" onclick="str(this.id)"/>
</th>
</tr>
<tr>
<th>
<input type="button" value="4" id="4" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="5" id="5" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="6" id="6" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="-" id="-" onclick="str(this.id)"/>
</th>
</tr>
<tr>
<th>
<input type="button" value="1" id="1" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="2" id="2" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="3" id="3" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="*" id="*" onclick="str(this.id)"/>
</th>
</tr>
<tr>
<th>
<input type="button" value="0" id="0" onclick="str(this.id)"/>
</th>
<th>
<input type="button" value="c" id="c" onclick="clearNum()"/>
</th>
<th>
<input type="button" value="=" id="=" onclick="eva()"/>
</th>
<th>
<input type="button" value="/" id="/" onclick="str(this.id)"/>
</th>
</tr>
</table>
</div>
</body>
</html>
效果图
制作一个计数器 如图，点击开始从1开始计数，点击停止，停止计数，点击复位归0并结束计数
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script type="text/javascript" src="../js/jquery.1.8.3.min.js" charset="UTF-8">
</script>
<script type="text/javascript">
var second = 0;
var minutes = 0;
function star() {
$("#start").attr("disabled", true);
$("#stop").attr("disabled", false);
t = setInterval("sum()", 10);
}
function sum() {
if(second != 100){
second++;
if(minutes<10){
if (second < 10 ) {
$("#text").val("0"+minutes+".0" + second);
} else if (second < 100) {
$("#text").val("0"+minutes+"."+second);
}
}else{
if (second < 10 ) {
$("#text").val(minutes+".0" + second);
} else if (second < 100) {
$("#text").val(minutes+"."+second);
}
}
}else{
second = 0;
minutes++;
}
}
function stop() {
$("#start").attr("disabled", false);
$("#stop").attr("disabled", true);
clearInterval(t);
}
function res() {
second = 0;
minutes = 0;
$("#text").val("00.00");
clearTimeout(t);
$("#start").attr("disabled", false);
$("#stop").attr("disabled", false);
}
</script>
<style type="text/css">
#start,
#res,
#stop,
#text{
border-radius: 25px;
margin-right: 20px;
}
div{
background-color: aliceblue;
width: 120px;
height: 90px;
margin: auto;
}
</style>
</head>
<body>
<div>
<table >
<tr>
<th colspan="2"><input type="text" style="width:50px; text-align: center; " value="00.00" id="text" /></th>
</tr>
<tr>
<th><input type="button" id="start" style="background-color: #7FFFD4;" value="开始"
onclick="star()" />
</th>
<th><input type="button" id="stop" style="background-color: bisque;" value="停止" onclick="stop()" />
</th>
</tr>
<tr>
<th colspan="2"><input type="button" id="res" style="background-color: #8A2BE2;" value="复位"
onclick="res()" />
</th>
</tr>
</table>
</div>
</body>
</html>
效果图：
