Storing and retrieving CGPoints inside an NSMutableArray

Question

I looked through countless questions here and elsewhere and I can’t understand for my life what I am doing wrong.

I am trying to save an array of CGPoints as NSValues ​​inside an NSMutableArray called such points on the iPhone:

NSValue *point = [NSValue valueWithCGPoint:firstTouch]; NSLog(@"NSValue *point = %@", point); [points addObject:point]; NSLOG OUTPUT NSValue *point = NSPoint: {120, 221} 

Everything goes smoothly from CGPoint to NSValue. But when I try to get the point, I get nothing.

 NSValue *getPoint = [points objectAtIndex:0]; CGPoint thePoint = [getPoint CGPointValue]; NSLog(@"Point = %@", NSStringFromCGPoint(thePoint)); NSLOG OUTPUT Point = {0, 0} 

The points should be the same, but I get a zero result.

For testing purposes, this happens in the touchhesBegan method.

Does anyone know where I am going wrong? Thanks in advance.

Answer 1

I never allocated my array to memory or initialized it. My points were not stored in the array because there was no array that existed.

Answer 2

to add CGPoint to NSMutableArray

 [ArrObj addObject:NSStringFromCGPoint(PointObj)]; 

to get CGPoint from NSMutableArray

 CGPoint pointObj2 = CGPointFromString([ArrObj objectAtIndex:index]); 

can it help you.

Answer 3

First allocate your modified array in memory:

 points = [[NSMutableArray alloc] init]; 

Then insert.