NSMutableArray get index

NSMutableArray *checkPassOrFail ;

 - (void) addyData :(NSString *) insertShowPassOrFail
 {
     
  [checkPassOrFail  insertObject:insertShowPassOrFail atIndex:0];
  [[NSUserDefaults standardUserDefaults] setObject:checkPassOrFail forKey:@"checkPassOrFail"];
  [[NSUserDefaults standardUserDefaults] synchronize];
     

}

.m

 -(NSArray *)checkPassOrFail
{
    
    //  Read it back
    NSMutableArray* checkPassOrFail = [NSMutableArray arrayWithArray:[[NSUserDefaults standardUserDefaults] objectForKey:@"checkPassOrFail"]];
        
    return checkPassOrFail;
    
}

.m

    int i = -1;
    for (NSString *showHistoryPassOrFaile in [[resultsScore sharedInstance] checkPassOrFail]) { //文字內容
            i = i+1;
   
       
        if ( [showHistoryPassOrFaile isEqualToString:@"pass"] ==1) {
            NSLog(@"pass checkHistoryPassOrFail = %@ by %d",[checkHistoryPassOrFail objectAtIndex:i],i);
            
   
        }
        
        if ( [showHistoryPassOrFaile isEqualToString:@"fail"] ==1) {
           NSLog(@"fail checkHistoryPassOrFail = %@ by %d",[checkHistoryPassOrFail objectAtIndex:i],i);
            
  
 
            }
        }
        

    }