1.下载 正则表达式RegexKitLite-4.0包，有个地址 http://download.csdn.net/detail/p709723778/4520214
2.将libicucore.dylib类库导入
3.将#import "RegexKitLite.h"加入
4.代码如下就ok，验证手机号是如下的string
NSString *regEx =@"\\b(1)[358][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]\\b";
[loginPrompt.plainTextField.textisMatchedByRegex:regEx]；如果匹配就返回yes；否则就返回no
5.如果要验证另一种格式的字符串，譬如说邮箱。只需将正则的内容改下即可，正则表达式并不是属于哪种语言，但是却很有必要学下。
准备工作，下载
RegexKitLite 软件包，解压后有2个文件，需要加载到project中。
然后还要加载framework libicucore.dylib ，因为RegexKitLite是调用这个里面的API,苹果规定过不能使用私有的api和没有发布的api。实际上RegexKitLite对NSString做了扩展，目前只支持NSString，对我来说也够了...
基本使用的例子（更多信息参看
官方文档 ）
1.
NSString *searchString = @ "This is neat." ;
NSString *regexString = @"(//w+)//s+(//w+)//s+(//w+)" ;
NSRange matchedRange = NSMakeRange(NSNotFound, 0UL);
NSError *error = NULL;
matchedRange = [searchString rangeOfRegex:regexString options:RKLNoOptions inRange:searchRange capture:2L error:&error];
NSLog(@"matchedRange: %@" , NSStringFromRange(matchedRange));
// 2008-03-18 03:51:16.530 test[51583:813] matchedRange: {5, 2}，//匹配到‘is‘
NSString *matchedString = [searchString substringWithRange:matchedRange];
NSLog(@"matchedString: '%@'" , matchedString);
// 2008-03-18 03:51:16.532 test[51583:813] matchedString: 'is' //生成子字符串
NSString *searchString = @"This is neat.";
NSString *regexString = @"(//w+)//s+(//w+)//s+(//w+)";
NSRange matchedRange = NSMakeRange(NSNotFound, 0UL);
NSError *error = NULL;
matchedRange = [searchString rangeOfRegex:regexString options:RKLNoOptions inRange:searchRange capture:2L error:&error];
NSLog(@"matchedRange: %@", NSStringFromRange(matchedRange));
// 2008-03-18 03:51:16.530 test[51583:813] matchedRange: {5, 2}，//匹配到‘is‘
NSString *matchedString = [searchString substringWithRange:matchedRange];
NSLog(@"matchedString: '%@'", matchedString);
// 2008-03-18 03:51:16.532 test[51583:813] matchedString: 'is' //生成子字符串
2.找到第一个匹配并返回一个NSString
NSString *searchString = @ "This is neat." ;
NSString *regexString = @"(//w+)//s+(//w+)//s+(//w+)" ;
NSString *matchedString = [searchString stringByMatching:regexString capture:2L];
NSLog(@"matchedString: '%@'" , matchedString);
// 2008-03-18 03:53:42.949 test[51583:813] matchedString: 'is'
NSString *searchString = @"This is neat.";
NSString *regexString = @"(//w+)//s+(//w+)//s+(//w+)";
NSString *matchedString = [searchString stringByMatching:regexString capture:2L];
NSLog(@"matchedString: '%@'", matchedString);
// 2008-03-18 03:53:42.949 test[51583:813] matchedString: 'is'
3.查找和替换，加括号和概念和Python中的一样，$1指代第一个括号中的内容
NSString *searchString = @ "This is neat." ;
NSString *regexString = @"//b(//w+)//b" ;
NSString *replaceWithString = @"{$1}" ;
NSString *replacedString = NULL;
replacedString = [searchString stringByReplacingOccurrencesOfRegex:regexString withString:replaceWithString];
//NSMutableString可以直接替换，并返回替换的次数
NSLog(@"replaced string: '%@'" , replacedString);
// 2008-07-01 19:03:03.195 test[68775:813] replaced string: '{This} {is} {neat}.'
NSMutableString *mutableString = [NSMutableString stringWithString:@"This is neat." ];
NSString *regexString = @"//b(//w+)//b" ;
NSString *replaceWithString = @"{$1}" ;
NSUInteger replacedCount = 0UL;
replacedCount = [mutableString replaceOccurrencesOfRegex:regexString withString:replaceWithString];
NSLog(@"count: %lu string: '%@'" , (u_long)replacedCount, mutableString);
// 2008-07-01 21:25:43.433 test[69689:813] count: 3 string: '{This} {is} {neat}.'
NSString *searchString = @"This is neat.";
NSString *regexString = @"//b(//w+)//b";
NSString *replaceWithString = @"{$1}";
NSString *replacedString = NULL;
replacedString = [searchString stringByReplacingOccurrencesOfRegex:regexString withString:replaceWithString];
//NSMutableString可以直接替换，并返回替换的次数
NSLog(@"replaced string: '%@'", replacedString);
// 2008-07-01 19:03:03.195 test[68775:813] replaced string: '{This} {is} {neat}.'
NSMutableString *mutableString = [NSMutableString stringWithString:@"This is neat."];
NSString *regexString = @"//b(//w+)//b";
NSString *replaceWithString = @"{$1}";
NSUInteger replacedCount = 0UL;
replacedCount = [mutableString replaceOccurrencesOfRegex:regexString withString:replaceWithString];
NSLog(@"count: %lu string: '%@'", (u_long)replacedCount, mutableString);
// 2008-07-01 21:25:43.433 test[69689:813] count: 3 string: '{This} {is} {neat}.'
4.用于拆分，返回一个拆分后的字符串数组
NSString *searchString = @ "This is neat." ;
NSString *regexString = @"//s+" ;
NSArray *splitArray = NULL;
splitArray = [searchString componentsSeparatedByRegex:regexString];
// splitArray == { @"This", @"is", @"neat." }
NSLog(@"splitArray: %@" , splitArray);
NSString *searchString = @"This is neat.";
NSString *regexString = @"//s+";
NSArray *splitArray = NULL;
splitArray = [searchString componentsSeparatedByRegex:regexString];
// splitArray == { @"This", @"is", @"neat." }
NSLog(@"splitArray: %@", splitArray);
5.返回所有匹配的字符串数组，这个例子中虽然有多个括号，但是 componentsMatchedByRegex不管
NSString *searchString = @ "$10.23, $1024.42, $3099" ;
NSString *regexString = @"//$((//d+)(?://.(//d+)|//.?))" ;
NSArray *matchArray = NULL;
matchArray = [searchString componentsMatchedByRegex:regexString];
// matchArray == { @"$10.23", @"$1024.42", @"$3099" };
NSLog(@"matchArray: %@" , matchArray);
6.返回所有匹配的字符串数组处理所有的括号
NSString *searchString = @"$10.23, $1024.42, $3099" ;
NSString *regexString = @"//$((//d+)(?://.(//d+)|//.?))" ;
NSArray *capturesArray = NULL;
capturesArray = [searchString arrayOfCaptureComponentsMatchedByRegex:regexString];
NSLog(@"capturesArray: %@" , capturesArray);
输出结果：
shell% ./capturesArray?
2009-05-06 03:25:46.852 capturesArray[69981:10b] capturesArray: (
(
"$10.23" ,
"10.23" ,
10,
23
),
(
"$1024.42" ,
"1024.42" ,
1024,
42
),
(
"$3099" ,
3099,
3099,
""
)
)
NSString *searchString = @"$10.23, $1024.42, $3099";
NSString *regexString = @"//$((//d+)(?://.(//d+)|//.?))";
NSArray *matchArray = NULL;
matchArray = [searchString componentsMatchedByRegex:regexString];
// matchArray == { @"$10.23", @"$1024.42", @"$3099" };
NSLog(@"matchArray: %@", matchArray);
6.返回所有匹配的字符串数组处理所有的括号
NSString *searchString = @"$10.23, $1024.42, $3099";
NSString *regexString = @"//$((//d+)(?://.(//d+)|//.?))";
NSArray *capturesArray = NULL;
capturesArray = [searchString arrayOfCaptureComponentsMatchedByRegex:regexString];
NSLog(@"capturesArray: %@", capturesArray);
输出结果：
shell% ./capturesArray?
2009-05-06 03:25:46.852 capturesArray[69981:10b] capturesArray: (
(
"$10.23",
"10.23",
10,
23
),
(
"$1024.42",
"1024.42",
1024,
42
),
(
"$3099",
3099,
3099,
""
)
)
