iOS中正则表达式的三种使用方式

正则语法努力学习中

一：使用NSPredicate(谓词)匹配

 NSString *mail = @"[email protected]";
 NSString *regex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
 NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
 BOOL isValid = [predicate evaluateWithObject:mail];

二：rangeOfString: option: 进行搜索

 NSString *text = @"// Do any additional setup after loading the view, typically from a nib.";
 NSRange range  = [text rangeOfString:@"(?:[^,])*\\." options:NSRegularExpressionSearch];
    if (range.location != NSNotFound) {
        NSLog(@"%@", [text substringWithRange:range]);
    }

三：使用iOS系统正则表达类

 NSString *text = @"// Do any additional setup after loading the typically from a nib. view, typically from a nib.";
 NSError *error = NULL;
 NSRegularExpression *regx = [NSRegularExpression regularExpressionWithPattern:@"(?:[^,])*\\." options:NSRegularExpressionCaseInsensitive error:&error];
   
    // 匹配多个
  NSArray *results = [regx matchesInString:text options:0 range:NSMakeRange(0, text.length)];
    [results enumerateObjectsUsingBlock:^(NSTextCheckingResult * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        NSLog(@"%@", obj);
        if (obj) {
            NSLog(@"多次匹配结果 ：%@", [text substringWithRange:obj.range]);
        }
    }];
   
    // 匹配单个
    NSTextCheckingResult *result = [regx firstMatchInString:text options:0 range:NSMakeRange(0, [text length])];
    if (result) {
        NSLog(@"%@", [text substringWithRange:result.range]);
    }