正则使用-OC

正则表达式基础篇
正则使用- swift篇

正则匹配 NSRegularExpression

1.正则中使用了\d,\b等，需要对 \ 做转义，使用转义字符\进行转义
2.NSRegularExpression初始化方法中的options设置为kNilOptions时区分大小写，严格验证；设置NSRegularExpressionCaseInsensitive不区分大小写，其它设置参考系统API

初始化

/// 初始化NSRegularExpression，如果出错则会返回nil，并带有error
/// @param pattern 正则表达式
/// @param options 模式选项, 设置kNilOptions时区分大小写
/// @parma error 错误
+ (nullable NSRegularExpression *)regularExpressionWithPattern:(NSString *)pattern options:(NSRegularExpressionOptions)options error:(NSError **)error;

关于NSRegularExpressionOptions

typedef NS_OPTIONS(NSUInteger, NSRegularExpressionOptions) {
   NSRegularExpressionCaseInsensitive             = 1 << 0,     /* Match letters in the pattern independent of case. */
   NSRegularExpressionAllowCommentsAndWhitespace  = 1 << 1,     /* Ignore whitespace and #-prefixed comments in the pattern. */
   NSRegularExpressionIgnoreMetacharacters        = 1 << 2,     /* Treat the entire pattern as a literal string. */
   NSRegularExpressionDotMatchesLineSeparators    = 1 << 3,     /* Allow . to match any character, including line separators. */
   NSRegularExpressionAnchorsMatchLines           = 1 << 4,     /* Allow ^ and $ to match the start and end of lines. */
   NSRegularExpressionUseUnixLineSeparators       = 1 << 5,     /* Treat only \n as a line separator (otherwise, all standard line separators are used). */
   NSRegularExpressionUseUnicodeWordBoundaries    = 1 << 6      /* Use Unicode TR#29 to specify word boundaries (otherwise, traditional regular expression word boundaries are used). */
};

返回所有匹配结果

/// 返回所有匹配结果，适合从一段字符串提取我们想要匹配的所有数据
- (NSArray<NSString *> *)matchesWithPattern:(NSString *)pattern validateString:(NSString *)validate {
    NSError *error = NULL;
    // options: NSRegularExpressionCaseInsensitive 不区分大小写
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:NSRegularExpressionCaseInsensitive error:&error];
    if (error) {
        NSLog(@"matchesWithPattern error: %@", error);
        return @[];
    }
    
    NSArray<NSTextCheckingResult *> *results = [regex matchesInString:validate options:0 range:NSMakeRange(0, validate.length)];
    NSMutableArray *mDatas = @[].mutableCopy;
    
    [results enumerateObjectsUsingBlock:^(NSTextCheckingResult * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        NSString *mathedStr = [validate substringWithRange:obj.range];
        [mDatas addObject:mathedStr];
    }];
    
    return mDatas;
}

测试用例：

NSString *pattern = @"^(10001|10002)$";
NSString *validate = @"10001";
NSArray *matches = [self matchesWithPattern:pattern validateString:validate];
NSLog(@"匹配结果：%@", matches);

打印结果：

匹配成功：(
10001
)

获取第1个匹配的结果

/// 获取第1个匹配的结果
- (NSString *)firstMatchWithPattern:(NSString *)pattern validateString:(NSString *)validate {
    NSError *error = NULL;
    // options: kNilOptions 区分大小写，严格验证
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:kNilOptions error:&error];
    if (error) {
        NSLog(@"firstMatchWithPattern error: %@", error);
        return @"";
    }
    
    NSTextCheckingResult *result = [regex firstMatchInString:validate options:0 range:NSMakeRange(0, validate.length)];
    NSString *mathedStr = [validate substringWithRange:result.range];
    return mathedStr;
}

测试用例：

// \d, \b等需要对\转义，需要使用转义字符进行转义
NSString *pattern = @"runoob(?=[\\d+])";
NSString *validate = @"runoob12runoobdrunooB3";
NSString *firstMatch = [self firstMatchWithPattern:pattern validateString:validate];
NSLog(@"匹配结果：%@", firstMatch);

打印结果：

匹配成功：runoob

获取匹配的数量

/// 获取匹配的数量
- (NSUInteger)numberOfMatchesWithPattern:(NSString *)pattern validateString:(NSString *)validate {
    NSError *error = NULL;
    // options: kNilOptions 区分大小写，严格验证
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:kNilOptions error:&error];
    if (error) {
        NSLog(@"firstMatchWithPattern error: %@", error);
        return 0;
    }
    
    NSUInteger number = [regex numberOfMatchesInString:validate options:kNilOptions range:NSMakeRange(0, validate.length)];
    
    return number;
}

测试用例：

// \d, \b等需要对\转义，需要使用转义字符进行转义
NSString *pattern = @"runoob(?=[\\d+])";
NSString *validate = @"runoob12runoobdrunooB3";
NSUInteger number = [self numberOfMatchesWithPattern:pattern validateString:validate];
NSLog(@"匹配数量：%lu", (unsigned long)number);

打印结果：

匹配数量：1

字符串正则替换

/// 字符串正则替换
- (NSString *)matchReplaceWithPattern:(NSString *)pattern validateStr:(NSString *)validate replacingStr:(NSString *)replacingStr {
    NSError *error = NULL;
    // options: kNilOptions 区分大小写，严格验证
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:kNilOptions error:&error];
    if (error) {
        NSLog(@"firstMatchWithPattern error: %@", error);
        return validate;
    }
    
    NSString *newStr = [regex stringByReplacingMatchesInString:validate options:0 range:NSMakeRange(0, validate.length) withTemplate:replacingStr];
    return newStr;
}

测试用例：

NSString *replacePattern = @"[0-9]+";
NSString *validateStr = @"12-ab-3-c";
NSString *replacingStr = @"ufo";
NSString *newStr = [self matchReplaceWithPattern:replacePattern validateStr:validateStr replacingStr:replacingStr];
NSLog(@"替换后：%@", newStr);

打印结果：

替换后：ufo-ab-ufo-c