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 match search replace split 6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-q1-4
]/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
- <script language="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>
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2 复杂分组
- <script language="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( and dad)?)/; 匹配出 mom 或 mon and daa
- //-->
- </script>
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3 反向引用
- <script language="JavaScript">
- <!--
-
-
- var sToMatch = "#123456789";
- var reNumbers = /#(d+)/;
- reNumbers.test(sToMatch);
- alert(RegExp.$1);
-
-
-
-
- var sToChange = "1234 5678";
- var reMatch = /(d{4}) (d{4})/;
- var sNew = sToChange.replace(reMatch,"$2 $1");
- alert(sNew);
-
-
-
- //-->
- </script>
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4 候选
- <script language="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>
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5 非捕获性分组
- <script language="JavaScript">
- <!--
-
-
- var sToMatch = "#123456789";
- var reNumbers = /#(?:d+)/;
- reNumbers.test(sToMatch);
- alert(RegExp.$1);
-
-
-
- var sToMatch = "#123456789";
- var reNumbers = /#(?:d+)/;
- alert(sToMatch.replace(reNumbers,"abcd$1"));
-
-
- //-->
- </script>
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6 前瞻
- <script language="JavaScript">
- <!--
-
-
-
- var sToMatch1 = "bedroom";
- var sToMatch2 = "bedding";
- var reBed = /bed(?=room)/;
- alert(reBed.test(sToMatch1)); //true
- alert(reBed.test(sToMatch2)); //false
-
- //负向前瞻
-
- var sToMatch1 = "bedroom";
- var sToMatch2 = "bedding";
- var reBed = /bed(?!room)/;
- alert(reBed.test(sToMatch1)); //false
- alert(reBed.test(sToMatch2)); //true
- //-->
- </script>
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7 边界
- <script language="JavaScript">
- <!--
-
-
- var sToMatch = "Important word is the last one.";
- var reLastWord = /(w+).$/;
- reLastWord.test(sToMatch);
- alert(RegExp.$1); //one
-
-
-
-
-
- var sToMatch = "Important word is the last one.";
- var reLastWord = /^(w+)/;
- reLastWord.test(sToMatch);
- alert(RegExp.$1); //Important
-
-
-
- var sToMatch = "Important word is the last one.";
- var reLastWord = /^(.+?)/;
- reLastWord.test(sToMatch);
- alert(RegExp.$1); //Important
-
-
-
- var data = " First second thind fourth fifth sixth ";
- var reCat = /(S+?)/g;
- var arrdata = data.match(reCat);
-
- for (var i = 0; i < arrdata.length; i++)
- {
- alert(arrdata[i]);
- }
-
-
- //-->
- </script>
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8 多行模式
- <script language="JavaScript">
- <!--
-
-
- var data = " First second
thind fourth
fifth sixth";
- var reCat = /(w+)$/g;
- var arrdata = data.match(reCat);
-
- for (var i = 0; i < arrdata.length; i++)
- {
- alert(arrdata[i]);
- }
-
-
- var data = " First second
thind fourth
fifth sixth";
- var reCat = /(w+)$/gm;
- var arrdata = data.match(reCat);
-
- for (var i = 0; i < arrdata.length; i++)
-
- {
- alert(arrdata[i]);
- } a
-
-
- //-->
- </script>
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转载出处:http://www.ok22.org/art_detail.aspx?id=209【js的正则方法使用实例】幸凡在线学习网 |