iOS/iPhone:从正则表达式中提取组（NSRegularExpression）

Posted 2021-02-24

Extract groups from a Regular Expression

NSRegularExpression* exp = [NSRegularExpression regularExpressionWithPattern:@"(put)-(expression)-(here)" options:NSRegularExpressionSearch error:&error];
 
if (error) {
    NSLog(@"%@", error);   
} else {
 
    NSTextCheckingResult* result = [exp firstMatchInString:testString options:0 range:NSMakeRange(0, [productDescription length] ) ];
 
    if (result) {
 
        NSRange groupOne = [result rangeAtIndex:1]; // 0 is the WHOLE string.
        NSRange groupTwo = [result rangeAtIndex:2];
        NSRange groupThree = [result rangeAtIndex:3];
 
        NSLog( [testString substringWithRange:groupOne] );
        NSLog( [testString substringWithRange:groupTwo] );
        NSLog( [testString substringWithRange:groupThree] );
    } 
}