NSMutable Array crashed when being accessed at other method - ios

Question

-(void)Aray
{
NSMutableArray *ColorArray = [[NSMutableArray alloc] init];
if(Counter < NewColor)
{
[ColorArray addObject:[NSNumber numberWithInteger:ColorTemp]];
Counter += 1;
}
}
-(IBAction)Go:(id)sender
{
NSMutableArray *ColorArray = [[NSMutableArray alloc] init];
Color = [[ColorArray objectAtIndex:Index] intValue];
if(Color == 2)
{
ColorLabel.text = #"The Color is Black";
Screen.image = [UIImage imageNamed:#"BlackTile.png"];
}
else
{
Screen.image = [UIImage imageNamed:#"Tunnel.png"];
ColorLabel.text = #"The Color is Green";
}
Index += 1;
}
-(IBAction)Black:(id)sender
{
ColorTemp = 2;
NewColor += 1;
[self Array];
}
-(IBAction)Green:(id)sender
{
ColorTemp = 1;
NewColor += 1;
[self Array];
}

Answer 1

The issue is that the ColorArray needs to be an instance variable (or #property) of the class so that it persists outside of the method calls.
This code will always crash, regardless of the value of Index:
NSMutableArray *ColorArray = [[NSMutableArray alloc] init];
Color = [[ColorArray objectAtIndex:Index] intValue];
Color appears to already be an instance variable (or #property), so this concept should not be alien to you.
Side note: variables conventionally start with lower case and use camal-case naming.