<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script>
window.onload=function(){
var oIput1=document.getElementById('put1');
var oIput2=document.getElementById('put2');
var nAdd=document.getElementById('add');
var nSub=document.getElementById('subtraction');
//上面的都是在window執行時立即執行
nAdd.onclick=function(){
var a=Number(oIput1.value);
var b=Number(oIput2.value);
//在點擊時間發生時才會執行
c = a+b;
alert(c);
}
nSub.onclick=function(){
var a=Number(oIput1.value);
var b=Number(oIput2.value);
c = a-b;
alert(c);
}
}
</script>
</head>
<body>
數值1:<input id="put1" type="text" value=""/>
數值2：<input id="put2" type="text" value=""/>
<input type="button" id="add" value="求和" />
<input type="button" id="subtraction" value="相減" />
</body>
</html>
下面是效果圖 ↓
