使用正则表达式
控制文本框只能输入数字
<input onkeyup="value=value.replace(/[^0-9]/g,'')" onpaste="value=value.replace(/[^0-9]/g,'')" oncontextmenu = "value=value.replace(/[^0-9]/g,'')">
<!DOCTYPE html><html>
<head>
<meta charset="utf-8" />
<title>正则 只能输入数字</title>
<meta name="Keywords" content="" />
<meta name="Description" content="" />
<link rel="stylesheet" href="css/.css" />
</head>
<body>
<input type="text" id="txt" />
<button id="btn">确定</button>
<script>
var txt = document.getElementById('txt')
var btn = document.getElementById('btn')
var reg = /^\d*$/
btn.onclick = function(){
var val = txt.value
if( !reg.test(val)){
alert('只能输入数字！')
}
}
</script>
</body>
</html>
