Greetings,
I'm trying to simply compare a NSString to an NSArray.
Here is my code:
NSString *username=uname.text;
NSString *regex=@"^[a-zA-Z0-9-_.]{3,20}$";
NSArray *matchArray=nil;
matchArray=[username componentsMatchedByRegex:regex];
if(matchArray[0] == "asdf"){ //this line causes the problem!
NSLog(@"matchArray %@",matchArray);
}
I get an "invalid operands to binary ==" error.
How can I compare the string?
Many thanks in advance,
You are trying to compare an NSString to a C string (char *), which is wrong. matchArray is an NSArray so you cannot treat it as a C array either, you have to use its objectAtIndex: method and pass in the index.
Use this instead:
if ([[matchArray objectAtIndex:0] isEqualToString:@"asdf"]) {
NSLog(@"matchArray %@", matchArray);
}
Addressing your comments, the reason why isEqualToString: does not show up in autocomplete is because Xcode cannot guess that matchArray contains NSStrings (it only knows it contains ids, that is, arbitrary Objective-C objects). If you really wanted to be sure, you can perform an explicit cast, but it doesn't matter if you don't:
if ([(NSString *)[matchArray objectAtIndex:0] isEqualToString:@"asdf"]) {
NSLog(@"matchArray %@", matchArray);
}
you want to use -objectAtIndex to get the array element. NOT the C array accessor syntax
[[matchArray objectAtIndex:0] isEqualTo: @"asd"]try to use:
[[matchArray objectAtIndex:0] isEqualToString:@"asdf"];
anyway the string "asdf" should be @"asdf"
