Testing if NSMutableArray contains a string object

Question

I have a NSMutableArray which contains a few NSString objects. How can I test if the array contains a particular string literal?

I tried

Answer 1

Comparing against string literals only works in code examples. In the real world you often need to compare against NSString* instances in e.g. an array, in which case containsObject fails because it compares against the object, not the value.

You could add a category to your implementation which extends NS(Mutable)Array with a method to check wether it contains the string (or whatever other type you need to compare against);

@implementation NSMutableArray (ContainsString)
-(BOOL) containsString:(NSString*)string
{
  for (NSString* str in self) {
    if ([str isEqualToString:string])
      return YES;
  }
  return NO; 
}
@end