javascript正则表达式

javascript正则表达式

regular expression是一个描述字符模式的对象；
ECMAScript中的RegExp类表示正则表达式；
String和RegExp都定义了使用正则表达式进行强大的模式匹配、文本检索和替换的函数；
正则表达式主要用来验证客户端的输入数据；

 

Ⅰ.创建正则表达式

类似于创建字符串，可以使用new运算符也可以采用字面值；

参数 含义
g 全局匹配
i 忽略大小写
m 多行匹配

下文中的javascript代码是通过 EclipseKepler 的 rhino 解释的
代码如下：

 　

/**
* new运算符创建正则表达式
*/
var box1 =newRegExp('box');//第一个参数是模式字符串
print('box1 = '+ box1);
var box2 =newRegExp('box','gim');//第二个参数是模式修饰符
print('box2 = '+ box2);

/**
* 字面值创建正则表达式
*/
var box3 =/Box/;//字面值方式的正则表达式
print('box3 = '+ box3);
var box4 =/Box/ig;//在第二个斜杠后加上模式修饰符
print('box4 = '+ box4);

运行结果如下：

box1 = /box/
box2 = /box/gim
box3 = /Box/
box4 = /Box/gi
 

Ⅱ.测试正则表达式

RegExp对象包含两个方法，test()和exec()

方法 功能
test 在字符串中测试模式匹配，返回true或false
exec 在字符串中执行匹配搜索，返回结果数组

代码如下：

/**
* new创建的正则表达式的test
*/
var pattern =newRegExp('box');//验证test
var str1 ='box';
var str2 ='Box';
print('pattern.test(str1) = '+ pattern.test(str1));
print('pattern.test(str2) = '+ pattern.test(str2));
var pattern2 =newRegExp('box','i');//不区分大小写
print('pattern2.test(str1) = '+ pattern2.test(str1));
print('pattern2.test(str2) = '+ pattern2.test(str2));

/**
* 使用一条语句实现的正则匹配
*/
var pattern3 =/box/i;
var str3 ='This is a Box';
print("pattern3.test(str3) = "+ pattern3.test(str3));
print("/box/i.test('This is a Box') = "+/box/i.test('This is a Box'));

/**
* exec方法
* 返回匹配到的字符串数组，如果没有就返回null
*/
var pattern4 =/box/i;
var ret1 = pattern4.exec(str3);
print("ret1 = "+ ret1);
print("typeof ret1 = "+typeof ret1);
var str4 ='ssss';
var ret2 = pattern4.exec(str4);
print("ret2 = "+ ret2);
print("typeof ret2 = "+typeof ret2);
print("typeof null = "+typeofnull);

运行结果如下：

pattern.test(str1) = true
pattern.test(str2) = false
pattern2.test(str1) = true
pattern2.test(str2) = true
pattern3.test(str3) = true
/box/i.test('This is a Box') = true
ret1 = Box
typeof ret1 = object
ret2 = null
typeof ret2 = object
typeof null = object
 

Ⅲ.字符串的正则表达式方法

String对象提供了4个使用正则表达式的方法

方法 含义
match(pattern) 返回pattern中的子串或null
search(pattern) 返回字符串中pattern的开始位置
replace(pattern, replacement) 用replacement替换pattern
split(pattern) 返回字符串按指定pattern拆分的数组

代码如下：

/**
* match方法
* 如果不开启全局就只返回匹配到的第一个字符串
* 如果开启全局就返回所有的被匹配字符串数组
*/
var pattern1 =/box/;
var pattern2 =/box/g;//开启全局
var str ='This is a box, That is a box!';
print("str.match(pattern1) = "+ str.match(pattern1));
var ret1 = str.match(pattern2);
print("ret1 = "+ ret1);
print("ret1[0] = "+ ret1[0]);

/**
* search方法
* 返回第一个匹配的位置，这里没有必要设置全局
* 找不到返回-1
*/
var pattern3 =/box/;
var ret2 = str.search(pattern3);
print("ret2 = "+ ret2);
print("'This is a BOX!'.search(pattern3) = "+'This is a BOX!'.search(pattern3));

/**
* replace方法
* 需要设置全局才会替换所有匹配到的字符串
*/
var str2 ='This is a box, That is a Box!';
var pattern4 =/box/i;
var pattern5 =/box/ig;
var replacement ='tom';
var ret3 = str.replace(pattern4, replacement);
var ret4 = str.replace(pattern5, replacement);
print("ret3 = "+ ret3);
print("ret4 = "+ ret4);

/**
* split方法
*/
var str3 ='This is a box! That is a Box!';
var pattern6 =/!/g;
var pattern7 =/ /g;
var ret5 = str3.split(pattern6);
var ret6 = str3.split(pattern7);
print("ret5 = "+ ret5);
print("ret5.length = "+ ret5.length);
print("ret6 = "+ ret6);
print("ret6.length = "+ ret6.length);

运行结果如下：

str.match(pattern1) = box
ret1 = box,box
ret1[0] = box
ret2 = 10
'This is a BOX!'.search(pattern3) = -1
ret3 = This is a tom, That is a box!
ret4 = This is a tom, That is a tom!
ret5 = This is a box, That is a Box,
ret5.length = 3
ret6 = This,is,a,box!,That,is,a,Box!
ret6.length = 8
 

Ⅳ.正则表达式静态属性

属性 短名 含义
input $_ 当前被匹配的字符串
lastMatch $& 最后一个匹配字符串
lastParen $+ 最后一对圆括号内的匹配子串
leftContext $` 最后一次匹配前的子串
rightContext $' 上次匹配之后的子串
multiline $* 用于指定是否所有的表达式都用于多行的布尔值

代码如下：

/**
* 正则表达式静态属性
*/
print("RegExp.input = "+RegExp.input);
var pattern =/google/i;
var str ='This is a google! That is a GOOGLE!';
pattern.test(str);//必须执行一下，静态属性才有效
//需要在浏览器中使用alert运行才能打印出当前的匹配字符串
print("RegExp.input = "+RegExp.input);
print("RegExp.leftContext = "+RegExp.leftContext);
print("RegExp.rightContext = "+RegExp.rightContext);
print("RegExp.lastMatch = "+RegExp.lastMatch);
var pattern2 =/(g)oogle/i;
var str2 ='This is a gogle! That is a GOOGLE!';
pattern2.test(str2);
print("RegExp.lastParen = "+RegExp.lastParen);//会打印匹配的在圆括号里字符串
print("RegExp.multiline = "+RegExp.multiline);

/**
* 所有的属性可以通过短名来操作
*/
var pattern3 =/google/i;
var str3 ='This is a google! That is a GOOGLE!';
pattern3.test(str3);
print("RegExp['$&'] = "+RegExp['$&']);
print("RegExp.$_ = "+RegExp.$_);

运行结果如下：

RegExp.input =
RegExp.input =
RegExp.leftContext = This is a
RegExp.rightContext = ! That is a GOOGLE!
RegExp.lastMatch = google
RegExp.lastParen = G
RegExp.multiline = false
RegExp['$&'] = google
RegExp.$_ =
 

Ⅴ.正则表达式实例属性

属性 含义
global 全局是否设置
ignoreCase 忽略大小写是否设置
multiline 多行是否设置
source 正则表达式的源字符串
lastIndex 下次匹配将从字符串的哪里开始

代码如下：

/**
* 正则表达式实例属性
*/
var pattern1 =/google/;
var pattern2 =/google/g;
var pattern3 =/google/ig;
var pattern4 =/google/igm;
print("pattern1.global = "+ pattern1.global);
print("pattern2.global = "+ pattern2.global);
print("pattern2.ignoreCase = "+ pattern2.ignoreCase);
print("pattern3.ignoreCase = "+ pattern3.ignoreCase);
print("pattern3.ignoreCase = "+ pattern3.multiline);
print("pattern4.ignoreCase = "+ pattern4.multiline);
print("pattern4.source = "+ pattern4.source);

/**
* lastIndex动态属性
*/
var str ='google google google';
print("pattern2.lastIndex = "+ pattern2.lastIndex);
for(var i =6;--i !=0;){
pattern2.test(str);
print("pattern2.lastIndex = "+ pattern2.lastIndex);
}
pattern2.lastIndex =100;
print("pattern2.lastIndex = "+ pattern2.lastIndex);

运行结果如下：

pattern1.global = false
pattern2.global = true
pattern2.ignoreCase = false
pattern3.ignoreCase = true
pattern3.ignoreCase = false
pattern4.ignoreCase = true
pattern4.source = google
pattern2.lastIndex = 0
pattern2.lastIndex = 6
pattern2.lastIndex = 13
pattern2.lastIndex = 20
pattern2.lastIndex = 0
pattern2.lastIndex = 6
pattern2.lastIndex = 100
 

Ⅵ.获取控制

正则表达式元字符是包含特殊含义的字符，
它们可以控制匹配模式的方式，
反斜杠后的元字符将失去其特殊意义。

元字符 匹配情况
. 匹配出换行符外的任意字符
 

1.点元字符，匹配除换行符外的任意字符

代码：

/**
* 点元字符：匹配除换行符外的任意字符
*/
var pattern1 =/g..gle/;
var str1 ='google';
print("pattern1.test(str1) = "+ pattern1.test(str1));
print("pattern1.test('g\\ngle') = "+ pattern1.test('g\ngle'));
print("pattern1.test('g12gle') = "+ pattern1.test('g12gle'));
print("pattern1.test('g3gle') = "+ pattern1.test('g3gle'));

运行结果：

pattern1.test(str1) = true
pattern1.test('g\ngle') = false
pattern1.test('g12gle') = true
pattern1.test('g3gle') = false
 

2.重复字符

元字符 匹配情况
x* 匹配0个或多个x
x? 匹配0个或1个x
x+ 匹配1个或多个x
(xyz)+ 匹配1个或多个(xyz)
x{m,n} 匹配m个到n个x

其中，前面的x也可以与点元字符一起使用，
例如：/.?/表示0个或一个任意字符

代码：

 
  1. /**
  2. * 重复字符
  3. */
  4. var pattern1 =/go*gle/;
  5. var str1 ='gooooooogle';
  6. print("pattern1.test(str1) = "+ pattern1.test(str1));
  7. print("pattern1.test('gobbbgle') = "+ pattern1.test('gobbbgle'));
  8. print("pattern1.test('go12gle') = "+/go+gle/.test('go12gle'));
  9. print("pattern1.test('ggle') = "+ pattern1.test('ggle'));
  11. var pattern2 =/go+gle/;
  12. print("pattern2.test(str1) = "+ pattern2.test(str1));
  13. print("pattern2.test('gogle') = "+ pattern2.test('gogle'));
  14. print("pattern2.test('ggle') = "+ pattern2.test('ggle'));
  16. var pattern3 =/go?gle/;
  17. print("pattern3.test(str1) = "+ pattern3.test(str1));
  18. print("pattern3.test('gogle') = "+ pattern3.test('gogle'));
  19. print("pattern3.test('ggle') = "+ pattern3.test('ggle'));
  20. print("pattern3.test('gXgle') = "+ pattern3.test('gXgle'));
  22. var pattern4 =/g.?gle/;
  23. print("pattern4.test('ggle') = "+ pattern4.test('ggle'));
  24. print("pattern4.test('gXgle') = "+ pattern4.test('gXgle'));
  25. print("pattern4.test('gXXgle') = "+ pattern4.test('gXXgle'));
  27. var pattern5 =/go{2,4}gle/;
  28. var str2 ='google';
  29. print("pattern5.test(str2) = "+ pattern5.test(str2));
  30. print("pattern5.test('goooogle') = "+ pattern5.test('goooogle'));
  31. print("pattern5.test('gooooogle') = "+ pattern5.test('gooooogle'));
  32. print("pattern5.test('ggle') = "+ pattern5.test('ggle'));
  34. var pattern6 =/go{3}gle/;
  35. print("pattern6.test('google') = "+ pattern6.test('google'));
  36. print("pattern6.test('gooogle') = "+ pattern6.test('gooogle'));
  37. print("pattern6.test('goooogle') = "+ pattern6.test('goooogle'));
  39. var pattern7 =/go{3,}gle/;
  40. print("pattern7.test('google') = "+ pattern7.test('google'));
  41. print("pattern7.test('gooogle') = "+ pattern7.test('gooogle'));
  42. print("pattern7.test('gooooooogle') = "+ pattern7.test('gooooooogle'));

运行结果：

pattern1.test(str1) = true
pattern1.test('gobbbgle') = false
pattern1.test('go12gle') = false
pattern1.test('ggle') = true
pattern2.test(str1) = true
pattern2.test('gogle') = true
pattern2.test('ggle') = false
pattern3.test(str1) = false
pattern3.test('gogle') = true
pattern3.test('ggle') = true
pattern3.test('gXgle') = false
pattern4.test('ggle') = true
pattern4.test('gXgle') = true
pattern4.test('gXXgle') = false
pattern5.test(str2) = true
pattern5.test('goooogle') = true
pattern5.test('gooooogle') = false
pattern5.test('ggle') = false
pattern6.test('google') = false
pattern6.test('gooogle') = true
pattern6.test('goooogle') = false
pattern7.test('google') = false
pattern7.test('gooogle') = true
pattern7.test('gooooooogle') = true
 

3.字符类匹配

元字符 匹配情况
. 除换行符外的任意字符
[a-z0-9] 括号中字符集中的任意字符
[^a-z0-9] 不在括号中字符集中的任意字符
\d 数字
\D 非数字
\w 字母数字下划线
\W 非字母数字下划线

代码：

 
  1. /**
  2. * [a-z]表示26个小写字母的任意一个
  3. */
  4. var pattern1 =/[a-z]oogle/;
  5. var str1 ='google';
  6. print("pattern1.test(str1) = "+ pattern1.test(str1));
  7. print("pattern1.test('boogle') = "+ pattern1.test('boogle'));
  8. print("pattern1.test('6oogle') = "+ pattern1.test('6oogle'));
  10. var pattern2 =/[A-Z]oogle/;
  11. print("pattern2.test(str1) = "+ pattern2.test(str1));
  12. print("/[A-Z]oogle/i.test(str1) = "+/[A-Z]oogle/i.test(str1));
  14. var pattern3 =/[0-9]oogle/;
  15. print("pattern3.test(str1) = "+ pattern3.test(str1));
  16. print("pattern3.test('4oogle') = "+ pattern3.test('4oogle'));
  17. print("pattern3.test('44oogle') = "+ pattern3.test('44oogle'));
  19. var pattern4 =/[0-9]*oogle/;//[0-9]*表示0个或多个数字
  20. print("pattern4.test('444oogle') = "+ pattern4.test('444oogle'));
  22. var pattern5 =/[a-zA-Z0-9]oogle/;
  23. print("pattern5.test('boogle') = "+ pattern5.test('boogle'));
  24. print("pattern5.test('Boogle') = "+ pattern5.test('Boogle'));
  25. print("pattern5.test('6oogle') = "+ pattern5.test('6oogle'));
  26. print("pattern5.test('oogle') = "+ pattern5.test('oogle'));
  28. var pattern6 =/[^0-9]oogle/;
  29. print("pattern6.test('444oogle') = "+ pattern6.test('444oogle'));
  30. print("pattern6.test('_oogle') = "+ pattern6.test('_oogle'));

运行结果：

pattern1.test(str1) = true
pattern1.test('boogle') = true
pattern1.test('6oogle') = false
pattern2.test(str1) = false
/[A-Z]oogle/i.test(str1) = true
pattern3.test(str1) = false
pattern3.test('4oogle') = true
pattern3.test('44oogle') = true
pattern4.test('444oogle') = true
pattern5.test('boogle') = true
pattern5.test('Boogle') = true
pattern5.test('6oogle') = true
pattern5.test('oogle') = false
pattern6.test('444oogle') = false
pattern6.test('_oogle') = true
 

4.锚元字符

元字符 匹配情况
^ 行首匹配
$ 行尾匹配
\A 只有匹配字符串开始处
\b 匹配单词边界，词在[]中时无效
\G 匹配当前搜索的开始位置
\Z 匹配字符串结束处或行尾
\z 只匹配字符串结束处

代码：

 
  1. /**
  2. * 锚元字符
  3. */
  4. var pattern1 =/^[0-9]oogle/;
  5. var pattern2 =/^[0-9]+oogle/;
  6. var str1 ='4oogle';
  7. var str2 ='4444oogle';
  8. print("pattern1.test(str1) = "+ pattern1.test(str1));
  9. print("pattern1.test(str2) = "+ pattern1.test(str2));
  10. print("pattern2.test(str1) = "+ pattern2.test(str1));
  11. print("pattern2.test(str2) = "+ pattern2.test(str2));
  13. var pattern3 =/\woogle/;
  14. var pattern4 =/\Woogle/;
  15. print("pattern3.test('aoogle') = "+ pattern3.test('aoogle'));
  16. print("pattern3.test('_oogle') = "+ pattern3.test('_oogle'));
  17. print("pattern3.test('-oogle') = "+ pattern3.test('-oogle'));
  18. print("pattern4.test('aoogle') = "+ pattern4.test('aoogle'));
  19. print("pattern4.test('_oogle') = "+ pattern4.test('_oogle'));
  20. print("pattern4.test('-oogle') = "+ pattern4.test('-oogle'));
  22. var pattern5 =/\doogle/;
  23. var pattern6 =/\Doogle/;
  24. print("pattern5.test('aoogle') = "+ pattern5.test('aoogle'));
  25. print("pattern5.test('9oogle') = "+ pattern5.test('9oogle'));
  26. print("pattern6.test('aoogle') = "+ pattern6.test('aoogle'));
  27. print("pattern6.test('9oogle') = "+ pattern6.test('9oogle'));
  29. var pattern7 =/^google/;
  30. var pattern8 =/^[a-z]oog[0-9]$/;
  31. var str3 ='This is google search engine';
  32. print("pattern7.test(str3) = "+ pattern7.test(str3));
  33. print("pattern8.test(str3) = "+ pattern8.test(str3));
  34. print("pattern8.test('google') = "+ pattern8.test('google'));
  35. print("pattern8.test('goog5') = "+ pattern8.test('goog5'));

运行结果：

pattern1.test(str1) = true
pattern1.test(str2) = false
pattern2.test(str1) = true
pattern2.test(str2) = true
pattern3.test('aoogle') = true
pattern3.test('_oogle') = true
pattern3.test('-oogle') = false
pattern4.test('aoogle') = false
pattern4.test('_oogle') = false
pattern4.test('-oogle') = true
pattern5.test('aoogle') = false
pattern5.test('9oogle') = true
pattern6.test('aoogle') = true
pattern6.test('9oogle') = false
pattern7.test(str3) = false
pattern8.test(str3) = false
pattern8.test('google') = false
pattern8.test('goog5') = true
 

5.空白字符

元字符 匹配情况
\0 null
\b 空格
\f 进纸
\n 换行
\r 回车
\t 制表
\s 空白空格制表换行
\S 非空白字符

代码：

 
  1. /**
  2. * 空白字符
  3. */
  4. var pattern1 =/goo gle/;
  5. var str1 ='goo gle';
  6. print("pattern1.test(str1) = "+ pattern1.test(str1));
  8. var pattern2 =/goo\sgle/;
  9. var str2 ='goo gle';
  10. print("pattern2.test(str2) = "+ pattern2.test(str2));
  11. print("/goo\\bgle/.test(str2) = "+/goo\bgle/.test(str2));
  13. var pattern3 =/google\b/;
  14. print("pattern3.test('google') = "+ pattern3.test('google'));
  15. print("pattern3.test('googleee') = "+ pattern3.test('googleee'));

运行结果：

pattern1.test(str1) = true
pattern2.test(str2) = true
/goo\bgle/.test(str2) = false
pattern3.test('google') = true
pattern3.test('googleee') = false
 

6.或匹配

被|隔开的字符串有一个匹配到就返回true

代码：

 
  1. var pattern1 =/google|baidu|bing/;
  2. var str1 ='bing';
  3. var str2 ='soso';
  4. var str3 ='this is google';
  5. print("pattern1.test(str1) = "+ pattern1.test(str1));
  6. print("pattern1.test(str2) = "+ pattern1.test(str2));
  7. print("pattern1.test(str3) = "+ pattern1.test(str3));

运行结果

pattern1.test(str1) = true
pattern1.test(str2) = false
pattern1.test(str3) = true
 

7.分组匹配

可以把分组后的字符串看成一个字符

元字符 匹配情况
(string) 用于反向引用的分组
\1或$1 匹配第一个分组中的内容
\2或$2 匹配第二个分组中的内容
\3或$3 匹配第三个分组中的内容

RegExp.$1表示获取模式中的一个分组对应的字符串，
在获取之前必须要运行一下正则表达式

代码：

 
  1. /**
  2. * 分组匹配
  3. */
  4. var pattern1 =/google{4,8}/;
  5. var pattern2 =/google{4,8}$/;
  6. var str1 ='googleeeeee';
  7. print("pattern1.test(str1) = "+ pattern1.test(str1));
  8. print("pattern1.test('googleeeeeeeeeee') = "+ pattern1.test('googleeeeeeeeeee'));
  9. print("pattern2.test('googleee') = "+ pattern2.test('googleee'));
  10. print("pattern2.test('googleeee') = "+ pattern2.test('googleeee'));
  11. print("pattern2.test('googleeeeeeeeeee') = "+ pattern2.test('googleeeeeeeeeee'));
  13. var pattern3 =/(google){4,8}$/;
  14. var str2 ='googlee';
  15. var str3 ='googlegooglegooglegoogle';
  16. print("pattern3.test(str2) = "+ pattern3.test(str2));
  17. print("pattern3.test(str3) = "+ pattern3.test(str3));
  20. /**
  21. * 获取匹配到的字符串
  22. */
  23. var pattern4 =/8(.*)8/;
  24. var pattern5 =/8.*8/;
  25. var str4 ='this is 8google8';
  26. print("pattern4.test(str4) = "+ pattern4.test(str4));
  27. print("RegExp.$1 = "+RegExp.$1);
  28. print("pattern5.test(str4) = "+ pattern5.test(str4));
  29. print("RegExp.$1 = "+RegExp.$1);
  31. var str5 ='this is a 8GooGle8';
  32. var ret1 = str5.replace(pattern4,'123');
  33. print("ret1 = "+ ret1);
  34. var ret2 = str5.replace(pattern4,'<strong>GooGle</strong>');
  35. print("ret2 = "+ ret2);
  36. var str6 ='this is a 8BaiDu8';
  37. var ret3 = str6.replace(pattern4,'<strong>$1</strong>');
  38. print("ret3 = "+ ret3);
  40. var pattern6 =/(.*)\s(.*)/;
  41. var str7 ='google baidu';
  42. var ret4 = str7.replace(pattern6,'$2 $1');
  43. print("ret4 = "+ ret4);

运行结果

pattern1.test(str1) = true
pattern1.test('googleeeeeeeeeee') = true
pattern2.test('googleee') = false
pattern2.test('googleeee') = true
pattern2.test('googleeeeeeeeeee') = false
pattern3.test(str2) = false
pattern3.test(str3) = true
pattern4.test(str4) = true
RegExp.$1 = google
pattern5.test(str4) = true
RegExp.$1 =
ret1 = this is a 123
ret2 = this is a <strong>GooGle</strong>
ret3 = this is a <strong>BaiDu</strong>
ret4 = baidu google
 

8.贪婪与惰性

贪婪 惰性
+ +?
? ??
* *?
{n} {n}?
{n,} {n,}?
{n,m} {n,m}?

代码：

 
  1. /**
  2. * 贪婪与惰性
  3. */
  4. var pattern1 =/[a-z]/;
  5. var pattern2 =/[a-z]+/;
  6. var pattern3 =/[a-z]+?/;
  7. var pattern4 =/[a-z]+?/g;
  8. var str1 ='abcdef';
  9. var ret1 = str1.replace(pattern1,'1');
  10. var ret2 = str1.replace(pattern2,'1');
  11. var ret3 = str1.replace(pattern3,'1');
  12. var ret4 = str1.replace(pattern4,'1');
  13. print("ret1 = "+ ret1);
  14. print("ret2 = "+ ret2);
  15. print("ret3 = "+ ret3);
  16. print("ret4 = "+ ret4);
  19. /**
  20. * 禁止了贪婪，开启了全局
  21. */
  22. var pattern5 =/8(.*)8/;
  23. var pattern6 =/8(.*?)8/;
  24. var pattern7 =/8(.*?)8/g;
  25. var str2 ='8google8 8google8 8google8 8google8';
  26. var ret5 = str2.replace(pattern5,'<strong>$1</strong>');
  27. var ret6 = str2.replace(pattern6,'<strong>$1</strong>');
  28. var ret7 = str2.replace(pattern7,'<strong>$1</strong>');
  29. print("ret5 = "+ ret5);
  30. print("ret6 = "+ ret6);
  31. print("ret7 = "+ ret7);
  34. /**
  35. * 除了正则表达式里两边的8不要匹配
  36. */
  37. var pattern8 =/8([^8]*)8/g;
  38. var pattern9 =/8(.*)8/g;
  39. var str3 ='8google8 8google8 8google8';
  40. var ret8 = str3.replace(pattern8,'<strong>$1</strong>');
  41. var ret9 = str3.replace(pattern9,'<strong>$1</strong>');
  42. print("ret8 = "+ ret8);
  43. print("ret9 = "+ ret9);

运行结果:

ret1 = 1bcdef
ret2 = 1
ret3 = 1bcdef
ret4 = 111111
ret5 = <strong>google8 8google8 8google8 8google</strong>
ret6 = <strong>google</strong> 8google8 8google8 8google8
ret7 = <strong>google</strong> <strong>google</strong> <strong>google</strong> <strong>google</strong>
ret8 = <strong>google</strong> <strong>google</strong> <strong>google</strong>
ret9 = <strong>google8 8google8 8google</strong>
 

9.返回数组

捕获性分组，所有的分组都捕获返回
非捕获性分组只需要在不需要捕获的分组前加上?:

代码：

 
  1. /**
  2. * 返回数组
  3. */
  4. var pattern1 =/^[a-z]+\s[0-9]{4}$/;
  5. var str1 ='google 2015';
  6. print("pattern1.test(str1) = "+ pattern1.test(str1));
  7. var ret1 = pattern1.exec(str1);
  8. print("ret1 = "+ ret1);
  9. print("typeof ret1 = "+typeof ret1);
  11. var pattern2 =/^[a-z]+/;
  12. var ret2 = pattern2.exec(str1);
  13. print("ret2 = "+ ret2);
  14. print("typeof ret2 = "+typeof ret2);
  17. /**
  18. * 分组返回
  19. */
  20. var pattern3 =/^([a-z]+)\s([0-9]{4})$/;
  21. var ret3 = pattern3.exec(str1);
  22. print("ret3 = "+ ret3);
  23. print("typeof ret3 = "+typeof ret3);
  24. print("ret3[0] = "+ ret3[0]);//匹配到的整个字符串
  25. print("ret3[1] = "+ ret3[1]);//匹配到的第1个字符串
  26. print("ret3[2] = "+ ret3[2]);//匹配到的第2个字符串
  29. /**
  30. * 捕获性分组，所有的分组都捕获返回
  31. * 非捕获性分组只需要在不需要捕获的分组前加上?:
  32. */
  33. var pattern4 =/(\d+)([a-z]+)/;
  34. var pattern5 =/(\d+)(?:[a-z]+)/;
  35. var str2 ='123abc';
  36. print("pattern4.exec(str2) = "+ pattern4.exec(str2));
  37. print("pattern5.exec(str2) = "+ pattern5.exec(str2));
  40. /**
  41. * 分组嵌套
  42. */
  43. var pattern6 =/(a?(b?(c?)))/;
  44. var str3 ='abc';
  45. var ret4 = pattern6.exec(str3);
  46. print("ret4 = "+ ret4);
  47. print("ret4[1] = "+ ret4[1]);//匹配到第1个分组(a?(b?(c?)))
  48. print("ret4[2] = "+ ret4[2]);//匹配到第2个分组(b?(c?))
  49. print("ret4[3] = "+ ret4[3]);//匹配到第3个分组(c?)

运行结果：

pattern1.test(str1) = true
ret1 = google 2015
typeof ret1 = object
ret2 = google
typeof ret2 = object
ret3 = google 2015,google,2015
typeof ret3 = object
ret3[0] = google 2015
ret3[1] = google
ret3[2] = 2015
pattern4.exec(str2) = 123abc,123,abc
pattern5.exec(str2) = 123abc,123
ret4 = abc,abc,bc,c
ret4[1] = abc
ret4[2] = bc
ret4[3] = c
 

10.前瞻捕获

匹配的字符串后面必须是另一个匹配的字符串

代码:

 
  1. /**
  2. * 前瞻捕获
  3. */
  4. var pattern1 =/goo(?=gle)/;
  5. var str1 ='goobbb';
  6. var str2 ='google';
  7. var ret1 = pattern1.exec(str1);
  8. var ret2 = pattern1.exec(str2);
  9. print("ret1 = "+ ret1);
  10. print("ret2 = "+ ret2);

运行结果：

ret1 = null
ret2 = goo
 

11.特殊字符匹配

代码:

 
  1. /**
  2. * 特殊字符匹配
  3. * 用反斜杠转义正则里的特殊字符才能匹配
  4. */
  5. var pattern2 =/\[/;
  6. var str3 ='[';
  7. var ret3 = pattern2.exec(str3);
  8. print("ret3 = "+ ret3);

运行结果：

ret3 = [
 

12.换行匹配

代码:

 
  1. /**
  2. * 换行模式
  3. */
  4. var pattern3 =/^\d+/;
  5. var pattern4 =/^\d+/g;
  6. var pattern5 =/^\d+/gm;
  7. var str3 ='1.baidu\n2.google\n3.bing';
  8. var ret3 = str3.replace(pattern3,'#');
  9. var ret4 = str3.replace(pattern4,'#');
  10. var ret5 = str3.replace(pattern5,'#');
  11. print("ret3 = \n"+ ret3);
  12. print("ret4 = \n"+ ret4);
  13. print("ret5 = \n"+ ret5);

运行结果：

ret3 =
#.baidu
2.google
3.bing
ret4 =
#.baidu
2.google
3.bing
ret5 =
#.baidu
#.google
#.bing
 

Ⅶ.常用正则表达式

代码如下：

 
  1. /**
  2. * 邮政编码
  3. * 必须是六位，必须是数字，首位不为零
  4. */
  5. var pattern1 =/[1-9][0-9]{5}/;
  6. var str1 ='This is 224000!';
  7. var ret1 = pattern1.test(str1);
  8. print("ret1 = "+ ret1);
  11. /**
  12. * 压缩文件
  13. * (文件名).(扩展名)
  14. */
  15. var pattern2 =/^\w+\.zip|gz|rar$/;
  16. var str2 ='213.zip';
  17. var ret2 = pattern2.test(str2);
  18. print("ret2 = "+ ret2);
  19. var str3 ='21-3.zip';
  20. var ret3 = pattern2.test(str3);
  21. print("ret3 = "+ ret3);
  24. /**
  25. * 删除空格
  26. */
  27. var pattern3 =/\s/g;
  28. var str4 ='111 222 33 44 555';
  29. var ret4 = str4.replace(pattern3,'');
  30. print("ret4 = "+ ret4);
  33. /**
  34. * 删除首尾空格
  35. */
  36. var pattern4 =/^\s+/;
  37. var str5 =' goo gle ';
  38. var ret5 = str5.replace(pattern4,'');
  39. print("ret5 = |"+ ret5 +"|");
  40. var pattern5 =/\s+$/;
  41. var ret6 = ret5.replace(pattern5,'');
  42. print("ret6 = |"+ ret6 +"|");
  45. /**
  46. * 删除首尾空格
  47. * 使用惰性模式的分组匹配
  48. */
  49. var pattern6 =/^\s+(.+)\s+$/;
  50. var str6 =' goo gle ';
  51. var ret7 = pattern6.exec(str6);
  52. var str7 = ret7[1];
  53. print("str7 = |"+ str7 +"|");
  55. var pattern7 =/^\s+(.+?)\s+$/;
  56. var str7 =' goo gle ';
  57. var ret8 = pattern7.exec(str7);
  58. var str8 = ret8[1];
  59. print("str8 = |"+ str8 +"|");
  61. var ret9 = str7.replace(pattern7,'$1');
  62. print("ret9 = |"+ ret9 +"|");
  65. /**
  66. * 简单电子邮件匹配
  67. */
  68. var pattern8 =/^([\w\.\-]+)@([\w\-]+)\.([a-zA-Z]{2,4})$/;
  69. var str8 ='yuki@163.com';
  70. var ret10 = pattern8.test(str8);
  71. print("ret10 = "+ ret10);

运行结果：

ret1 = true
ret2 = true
ret3 = false
ret4 = 1112223344555
ret5 = |goo  gle   |
ret6 = |goo  gle|
str7 = |goo  gle  |
str8 = |goo  gle|
ret9 = |goo  gle|
ret10 = true
 

Ⅷ.Another

运行上面的javascript代码使用的是Eclipse Kepler自带的Rhino解释器，
原来使用IntelliJ IDEA的童鞋可以试试用一下Eclipse Kepler。

本文的编辑使用了作业部落的css样式以及它们的markdown编辑器
点击可以访问原文：https://www.zybuluo.com/thorncorona/note/71406

如果觉得此文不错的话可以点击下面红色的小按钮关注我
更多文章请点击http://www.cnblogs.com/kodoyang/访问我的博客园主页。
大家阅读愉快。

参考链接：
- 李炎恢的正则表达式专题
- 参考w3school

孔东阳
二〇一五年二月十四日

最新文章

  1. 发布在即！.NET Core 1.0 RC2已准备就绪！！
  2. linux awk, xargs
  3. linux下快速删除大量文件
  4. CSS块级元素、内联元素概念
  5. Android Developers:两个视图渐变
  6. 在eclipse中对于java的操作
  7. 编写高质量代码改善python程序91个建议学习01
  8. linux杂记（十）what is BASH Shell
  9. python基本运算
  10. python 特殊方法实例
  11. Android简易实战教程--第五十话《动画扫描》
  12. 失去焦点布局在ios12-微信6.7.0版本以上不回滚的解决方案
  13. 玩转BLE(2)_使用bluepy扫描BLE的广播数据
  14. C# 的Chart
  15. LeetCode in action
  16. Linux下如何查看系统启动时间和运行时间(转)
  17. filedisk.sys
  18. Django基础三之视图函数
  19. PHP框架（如：laravel、yii2、thinkPHP5）中统一异常处理及统一日志打印
  20. 网站Seo纲领

热门文章

  1. C# 公关类（全）
  2. Hibernate —— ID的各种生成器（转）
  3. 《c程序设计语言》读书笔记--统计字符数
  4. 甲骨文推出MySQL Fabric，简化MySQL的高可用性与可扩展性
  5. Volley HTTP库系列教程(2)Volley.newRequestQueue示例,发请求的流程,取消请求
  6. BZOJ 1415 聪聪和可可（概率DP）
  7. Android 工程在4.0基础上混淆
  8. POJ3415 Common Substrings
  9. Oracle数据库之一
  10. HDU 1422 重温世界杯