入力ボックスに正当なIPアドレスがあるかどうかを検出します.
1.第一の方法:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title> IP </title>
<script language="javascript">
function check(){
str = formdata.txt.value;
str = str.match(/(\d+)\.(\d+)\.(\d+)\.(\d+)/g);
if (str == null){
alert(" ");
return false;
}else if (RegExp.$1>255 || RegExp.$2>255 || RegExp.$3>255 || RegExp.$4>255){
alert(" IP ");
return false;
}else{
alert(" IP ");
return true;
}
}
</script>
</head>
<body>
<form name="formdata" onSubmit="return check()">
<input type="text" name="txt">
<input type="submit" value=" ">
</form>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</HEAD>
<BODY>
<title>IP js - </title>
IP ：<input type="text" id="ip">
<input type="button" onclick="checkIP()" value=" ">
</BODY>
</HTML>
<script language="javascript">
function checkIP()
{
obj = document.getElementById("ip").value;
//ip
var exp=/^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/;
var reg = obj.match(exp);
if(reg==null)
{
alert("IP ！");
}
else
{
alert("IP ！");
}
}
</script>