简单手机拨号器制作（练习）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<input type="text" id="a" style="text-align: right;">
<div id="number">
<input type="submit" id="b1" value="1"></input>
<input type="submit" id="b2" value="2"></input>
<input type="submit" id="b3" value="3"></input>
<input type="submit" id="b4" value="4"></input>
<input type="submit" id="b5" value="5"></input>
<input type="submit" id="b6" value="6"></input>
<input type="submit" id="b7" value="7"></input>
<input type="submit" id="b8" value="8"></input>
<input type="submit" id="b9" value="9"></input>
<input type="submit" id="c" value="0"></input>
<input type="submit" id="d" value="."></input>
<br />
<input type="submit" id="e" value="+"></input>
<input type="submit" id="f" value="-"></input>
<input type="submit" id="g" value="*"></input>
<input type="submit" id="h" value="/"></input>
<button id="i">c</button>
<button id="j">=</button>
</div>
<script>
var a=document.getElementById("a")
var v=document.getElementById("number")
var i=document.getElementById("i")
var j=document.getElementById("j")
number.onclick=function(ev){
var n=event||ev;
var m=n.srcElement||n.target;
if(m.type=="submit")
a.value+=m.value;
}
j.onclick=function(){
if(a.value!="")
a.value=eval(a.value);
}
i.onclick=function(){
a.value="";
}
</script>
</body>
</html>
