在代码开发过程中，我们经常需要用来校验邮箱、手机号等等，这个时候就需要用到正则表达式。在iOS开发中，能用来做正则校验的有两个 NSPredicate 和 NSRegularExpression 。
NSPredicate
NSPredicate 能用来简单做正则校验，但是它的问题是存在校验不出来的情况。
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//NSString+RegEx.h#import <Foundation/Foundation.h>@interface NSString (RegEx)#pragma mark - NSPredicate- (BOOL)mars_matchedByPrdicateToRegEx:(NSString *)regEx;@end//NSString+RegEx.m#import "NSString+RegEx.h"@implementation NSString (RegEx)#pragma mark - NSPredicate- (BOOL)mars_matchedByPrdicateToRegEx:(NSString *)regEx{ NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regEx]; return [predicate evaluateWithObject:self];}@end |
NSRegularExpression （推荐）
NSRegularExpression 相对于 NSPredicate 功能就强大的多了，这也是iOS正则校验的正统路子。
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//NSString+RegEx.h#import <Foundation/Foundation.h>@interface NSString (RegEx)#pragma mark - NSRegularExpression//校验是否匹配- (BOOL)mars_matchedToRegEx:(NSString *)regEx;//匹配到的第一个字符串- (NSString *)mars_firstMatchToRegEx:(NSString *)regEx;//所有匹配的字符串- (NSArray *)mars_matchesToRegEx:(NSString *)regEx;//替换匹配到的字符串- (NSString *)mars_stringByReplaceMatchesToRegEx:(NSString *)regEx replaceString:(NSString *)replaceString;@end//NSString+RegEx.m#import "NSString+RegEx.h"@implementation NSString (RegEx)#pragma mark - NSRegualrExpression//校验是否匹配- (BOOL)mars_matchedToRegEx:(NSString *)regEx{ NSError *error; NSRegularExpression *regularExpression = [NSRegularExpression regularExpressionWithPattern:regEx options:NSRegularExpressionCaseInsensitive error:&error]; NSUInteger number = [regularExpression numberOfMatchesInString:self options:0 range:NSMakeRange(0, self.length)]; return number != 0;}//匹配到的第一个字符串- (NSString *)mars_firstMatchToRegEx:(NSString *)regEx{ NSError *error; NSRegularExpression *regularExpression = [NSRegularExpression regularExpressionWithPattern:regEx options:NSRegularExpressionCaseInsensitive error:&error]; NSTextCheckingResult *firstMatch = [regularExpression firstMatchInString:self options:0 range:NSMakeRange(0, self.length)]; if (firstMatch) { NSString *result = [self substringWithRange:firstMatch.range]; return result; } return nil;}//所有匹配的字符串- (NSArray *)mars_matchesToRegEx:(NSString *)regEx{ NSError *error; NSRegularExpression *regularExpression = [NSRegularExpression regularExpressionWithPattern:regEx options:NSRegularExpressionCaseInsensitive error:&error]; NSArray *matchArray = [regularExpression matchesInString:self options:0 range:NSMakeRange(0, self.length)]; NSMutableArray *array = [NSMutableArray array]; if (matchArray.count != 0) { for (NSTextCheckingResult *match in matchArray) { NSString *result = [self substringWithRange:match.range]; [array addObject:result]; } } return array;}//替换匹配到的字符串- (NSString *)mars_stringByReplaceMatchesToRegEx:(NSString *)regEx replaceString:(NSString *)replaceString{ NSError *error; NSRegularExpression *regularExpression = [NSRegularExpression regularExpressionWithPattern:regEx options:NSRegularExpressionCaseInsensitive error:&error]; return [regularExpression stringByReplacingMatchesInString:self options:0 range:NSMakeRange(0, self.length) withTemplate:replaceString];}@end |
最后我们看到，还是推荐大家使用NSRegularExpression来做正则的校验，如果大家在学习中有更好的解决方法或者心得，可以在下方的留言区讨论。
