由于转载不了,直接复制粘贴过来了,本文不是本人所写,原文出处为http://bbs.html5cn.org/thread-574-1-10.html 有空看看,觉得写得还行
一 javascript正则表达式的基本知识
1 javascript正则对象创建 和用法
声明javascript 正则表达式
var reCat =new RegExp("cat");
你也可以
var reCat =/cat/; //Perl 风格 (推荐)
2 学习最常用的 test exec matchsearch replace split6个方法
1)test 检查指定的字符串是否存在
var data = "123123";
var reCat = /123/gi;
alert(reCat.test(data)); //true
//检查字符是否存在 g继续往下走 i 不区分大小写
2) exec 返回查询值
var data ="123123,213,12312,312,3,Cat,cat,dsfsdfs,";
var reCat = /cat/i;
alert(reCat.exec(data)); //Cat
3)match 得到查询数组
var data ="123123,213,12312,312,3,Cat,cat,dsfsdfs,";
var reCat = /cat/gi;
var arrMactches = data.match(reCat)
for (var i=0;i <arrMactches.length ; i++)
{
alert(arrMactches); //Cat cat
}
4)search 返回搜索位置 类似于indexof
var data ="123123,213,12312,312,3,Cat,cat,dsfsdfs,";
var reCat = /cat/gi;
alert(data.search(reCat)); //23
5)replace 替换字符 利用正则替换
var data ="123123,213,12312,312,3,Cat,cat,dsfsdfs,";
var reCat = /cat/gi;
alert(data.replace(reCat,"libinqq"));
6)split 利用正则分割数组
var data ="123123,213,12312,312,3,Cat,cat,dsfsdfs,";
var reCat = /,/;
var arrdata = data.split(reCat);
for (var i = 0; i <arrdata.length; i++)
{
alert(arrdata);
}
3 学习下 简单类 负向类 范围类 组合类
//简单类
var data ="1libinqq,2libinqq,3libinqq,4libinqq";
var reCat = /[123]libinqq/gi;
var arrdata = data.match(reCat);
for (var i = 0; i <arrdata.length; i++)
{
alert(arrdata); //1libinqq 2libinqq 3libinqq
}
//负向类
var data ="alibinqq,1libinqq,2libinqq,3libinqq,4libinqq"; //u0062cf
var reCat = /[^a123]libinqq/gi;
var arrdata = data.match(reCat);
for (var i = 0; i <arrdata.length; i++)
{
alert(arrdata); //4libinqq
}
//范围类
var data ="libinqq1,libinqq2,libinqq3,libinqq4,libinqq5"; //u0062cf
var reCat = /libinqq[2-3]/gi;
var arrdata = data.match(reCat);
for (var i = 0; i <arrdata.length; i++)
{
alert(arrdata); //libinqq2 libinqq3
}
//组合类
var data ="a,b,c,w,1,2,3,5"; //u0062cf
var reCat = /[a-q1-4n]/gi;
var arrdata = data.match(reCat);
for (var i = 0; i <arrdata.length; i++)
{
alert(arrdata); //a b c 1 2 3
}
二 javascript 正则表达式是分组知识
1) 简单分组
<scriptlanguage="JavaScript">
<!--
var data ="Ah-mousemouse";
var reCat =/(mouse){2}/gi;
var arrdata =data.match(reCat);
for (var i = 0; i < arrdata.length;i++)
{
alert(arrdata[i]);
}
//-->
</script>
2 复杂分组
<scriptlanguage="JavaScript">
<!--
var data = "bb ba da bad dad aa";
var reCat = /([bd]ad?)/gi; //匹配出 ba da bad dad
var arrdata =data.match(reCat);
for (var i = 0; i < arrdata.length;i++)
{
alert(arrdata[i]);
}
// 同时 也不介意将分组放在分组中间
// var re = /(mom( anddad)?)/; 匹配出mom 或 mon anddaa
//-->
</script>
3 反向引用
<scriptlanguage="JavaScript">
<!--
var sToMatch ="#123456789";
var reNumbers = /#(d+)/;
reNumbers.test(sToMatch);
alert(RegExp.$1);
var sToChange = "12345678";
var reMatch = /(d{4})(d{4})/;
var sNew = sToChange.replace(reMatch,"$2$1");
alert(sNew);
//-->
</script>
4 候选
<scriptlanguage="JavaScript">
<!--
var sToMatch1 = "red";
var sToMatch2 = "black";
var reRed = /red/;
var reBlack = /black/;
alert(reRed.test(sToMatch1) ||reBlack.test(sToMatch1));
alert(reRed.test(sToMatch2) ||reBlack.test(sToMatch2));
var sToMatch1 = "red";
var sToMatch2 = "black";
var reRedOrBlack =/(red|black)/;
alert(reRedOrBlack.test(sToMatch1));
alert(reRedOrBlack.test(sToMatch2));
//-->
</script>
5 非捕获性分组
<scriptlanguage="JavaScript">
<!--
var sToMatch ="#123456789";
var reNumbers =/#(?:d+)/;
reNumbers.test(sToMatch);
alert(RegExp.$1);
var sToMatch ="#123456789";
var reNumbers =/#(?:d+)/;
alert(sToMatch.replace(reNumbers,"abcd$1"));
//-->
</script>
6 前瞻
<scriptlanguage="JavaScript">
<!--
var sToMatch1 ="bedroom";
var sToMatch2 ="bedding";
var reBed =/bed(?=room)/;
alert(reBed.test(sToMatch1)); //true
alert(reBed.test(sToMatch2)); //false
//负向前瞻
var sToMatch1 ="bedroom";
var sToMatch2 ="bedding";
var reBed =/bed(?!room)/;
alert(reBed.test(sToMatch1));//false
alert(reBed.test(sToMatch2));//true
//-->
</script>
7 边界
<scriptlanguage="JavaScript">
<!--
var sToMatch = "Important word is the lastone.";
var reLastWord =/(w+).$/;
reLastWord.test(sToMatch);
alert(RegExp.$1); //one
var sToMatch = "Important word is the lastone.";
var reLastWord =/^(w+)/;
reLastWord.test(sToMatch);
alert(RegExp.$1); //Important
var sToMatch = "Important word is the lastone.";
var reLastWord =/^(.+?)b/;
reLastWord.test(sToMatch);
alert(RegExp.$1); //Important
var data = " First second thind fourth fifth sixth";