select indexOfObject from NSArray in Xcode by comp

Question

Hi I have NSarray values in Xcode. I need to get array indexOfObject by comparing string values. my array values are

 (
    {
    firstName = lord;
    lastname = krishna;
    },
    {
    firstName = priya;
    lastname = amirtha;
    }
 )

If I type first name in textfield and click button means last name want to display in another textfield.
thank you.

Answer 1

To answer the title of your question:

NSString *compareString = @"something";
NSMutableArray *indexesOfMatches = [[NSMutableArray alloc]init];

for (NSString *string in theArray) {

   if ([string isEqualToString:compareString]) {
       NSNumber *index = [[NSNumber numberWithInterger:[theArray indexOfObject:string]];
       [indexOfMatches addObject:index];
    }
}
    //indexOfMatches will now contain NSNumber objects that represent the indexes of each of the matching string objects in the array

I think that using an NSDictionary would be better for you though. Then you can simply keep the first and last names as Key Value pairs.

NSDictionary *names = @{@"lord" : @"krishna", @"priya" : @"amirtha" };

Then you can just do value for key when you get the first name:

NSString *firstName = @"lord";
NSString *lastName = [names valueForKey:firstName];

Answer 2

Store firstNameArray and lastNameArray a mutable array NSMutableArray.

Using Fast Enumeration. Suppose array is the array you are provided with

for (NSDictionary *item in array) {
        [firstNameArray addObject:[item objectForKey:@"firstName"]];
        [lastNameArray addObject:[item objectForKey:@"lastName"]];
    }

After entering the data in firstNameTextField click the button

Button action method implementation

-(IBAction)btnClicked:(id)sender {
  NSInteger index = [firstName indexOfObject:[firstNameTextField text]];
  [lastNameTextField setText:[lastName objectAtIndex:index]];
}