iOS中使用RegexKitLite來試用正則表達式

準備工作，下載RegexKitLite 軟件包，解壓後有2個文件，需要加載到project中。

然後還要加載framework libicucore.dylib ，因爲RegexKitLite是調用這個裏面的API,蘋果規定過不能使用私有的api和沒有發佈的api。實際上RegexKitLite對NSString做了擴展，目前只支持NSString，對我來說也夠了...

基本使用的例子（更多信息參看 官方文檔 ）
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

2.找到第一個匹配並返回一個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'

3.查找和替換，加括號和概念和Python中的一樣，$1指代第一個括號中的內容
NSString *searchString = @"This is neat."; NSString *regexString = @"//b(//w+)//b"; NSString *replaceWithString = @"{$1}"; NSString *replacedString = NULL; replacedString = [searchString stringByReplacingOccurrencesOfRegex:regexString withString:replaceWithString]; //NSMutableString可以直接替換，並返回替換的次數 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.用於拆分，返回一個拆分後的字符串數組
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數組，這個例子中雖然有多個括號，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數組處理所有的括號 NSString *searchString = @"$10.23, $1024.42, $3099"; NSString *regexString = @"//$((//d+)(?://.(//d+)|//.?))"; NSArray *capturesArray = NULL; capturesArray = [searchString arrayOfCaptureComponentsMatchedByRegex:regexString]; /* capturesArray == [NSArray arrayWithObjects: [NSArray arrayWithObjects: @"$10.23", @"10.23", @"10", @"23", NULL], [NSArray arrayWithObjects:@"$1024.42", @"1024.42", @"1024", @"42", NULL], [NSArray arrayWithObjects: @"$3099", @"3099", @"3099", @"", NULL], NULL]; */ NSLog(@"capturesArray: %@", capturesArray); 輸出結果： 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, "" ) )