How do I remove leading & trailing whitespace of NSString inside an NSArray?

Question

I have an NSArray declared as such:

@property (nonatomic, strong) NSArray *arrayRefineSubjectCode; 

I have the array elements manually filled out as below:

     arrayRefineSubjectCode = [NSArray arrayWithObjects:                               @"  BKKC 2061",                               @"   BKKS 2631   ",                               @"BKKS 2381      ",                               nil]; 

So how do I remove starting and ending whitespace and make each array elements to become as these:

     arrayRefineSubjectCode = [NSArray arrayWithObjects:                               @"BKKC 2061",                               @"BKKS 2631",                               @"BKKS 2381",                               nil]; 

I have tried using "stringByTrimmingCharactersInSet:" but it only works for NSString. Kinda confused here. Please help...

Answer 1

The NSArray and the contained NSString objects are all immutable. There's no way to change the objects you have.

Instead you have to create new strings and put them in a new array:

NSMutableArray *trimmedStrings = [NSMutableArray array]; for (NSString *string in arrayRefineSubjectCode) {     NSString *trimmedString = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];     [trimmedStrings addObject:trimmedString]; } arrayRefineSubjectCode = trimmedStrings;