Objective-C - Position Object with CGPoint from another Method - objective-c

Question

Hello i have got a question. I hope anybody could help me. I do not understand… I have a method returnPointFromArray where i have an array with values (e.g. 50.0, 100.0). Than i want to random it and then i want to use the CGPoint p in the Method drawObjectWithPoint to position my Object (object from another class) with the random value.
But the drawObjectWithPoint Method says always that the CGPoint p ist 0.0, 0,0 or he says "Use of undeclared identifier p or "instance variable hides…" .
I tried the same principle to test with int and this works.
I don´t know what i´m doing wrong.
It would be great if anybody could help me and explain what i´m doing wrong.
Thanks a lot.
.h
-(void)returnPointFromArray;
-(void)drawObjectWithPoint;
.m
-(void)returnPointFromArray
{
NSArray *points = [];
//Random for points
NSUInteger *randomIndex = arc4random() % [points count];
NSValue *val = [points objectAtIndex:randomIndex];
CGPoint p = [val CGPointValue];
}
-(void)drawObjectWithPoint
{
Object *myObject [[Object alloc]init];
CGPoint pNew = p;
myObject.position =
[self addChild:myObject];
}

Answer 1

You can do this: Edited: (This is how yo declare in .h file)
in .h file
#import <UIKit/UIKit.h>
#interface MyClass : UIViewController {
CGPoint p;
}
-(void)returnPointFromArray;
-(void)drawObjectWithPoint;
#end
in .m file
-(void)returnPointFromArray {
NSArray *points = [];
//Random for points
NSUInteger *randomIndex = arc4random() % [points count];
NSValue *val = [points objectAtIndex:randomIndex];
p = [val CGPointValue]; // change here
}
-(void)drawObjectWithPoint {
Object *myObject [[Object alloc]init];
CGPoint pNew = p;
myObject.position =
[self addChild:myObject];
}

Answer 2

assign value directly by method call
-(void)drawObjectWithPoint
{
Object *myObject [[Object alloc]init];
myObject.position = [self returnPointFromArray];
[self addChild:myObject];
}
-(CGPoint)returnPointFromArray {
NSArray *points = [];
//Random for points
NSUInteger *randomIndex = arc4random() % [points count];
NSValue *val = [points objectAtIndex:randomIndex];
return [val CGPointValue];
}

Answer 3

Just declared CGPoint p; in .h file. You declared it as locally(returnPointFromArray function) means its scope is local for that function only. check here
for reference.

Answer 4

Your returnPointFromArray method returns void - just modify it -
-(CGPoint)returnPointFromArray
{
// your code
return p;
}
Then where you want to use p, just write
CGPoint pNew = [self returnPointFromArray];
obviously you'll have to add code which actually uses this value - your code doesn't do this at all -
myObject.position = pNew;