Question

So I am new to Objective-C but not to OOP programming. I am trying to make a class that will add “Squares” to a NSMutableArray but when I wrote the class and ran my app, it crashed. Here is the Squares.h file:

#import <Foundation/Foundation.h>
#import "Square.h"

@interface Squares : NSObject {
    NSMutableArray *squares; }

-(id) init;
-(void) addSquare: (CGPoint) pos;
-(NSMutableArray *) getSquares;
-(void) update;
-(void) render;

@end

And here is the Squares.m file:

import “Squares.h”

@implementation Squares

-(id) init{
self = [super init]; if (self != nil) { squares = [[NSMutableArray alloc] init];

[self addSquare: CGPointMake(100, 100)];
      }
  return self; }

-(void) addSquare: (CGPoint) pos{
Square *square;
square = [[Square alloc] init];
[square setPosition: pos];

[squares addObject: square]; }

-(NSMutableArray *) getSquares{
return squares; }

-(void) update{
for (int i = 0; i < squares.count; i++){
Square *s;
s = [squares objectAtIndex: i];
[s move];

} }

-(void) render{
for (int i = 0; i < squares.count; i++){
Square *s;
s = [squares objectAtIndex: i];
[s render];

} }

@end

So is this not working just because I have programmed this wrong or not?

Answer 1

Instead of for (int i = 0; i <= squares.count; i++

try for (int i = 0; i < squares.count; i++