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Shaun Kelly
5,648 PointsAsterisk
Question One. What is the asterisk for in this code where is says -(SKAction*)? Is it because we are carrying an array ?
-(SKAction*) tapAction {
if (_tapAction != nil) {
return _tapAction;
}
NSArray *spaceCatTextures = @[[SKTexture textureWithImageNamed:@"spacecat_2"],
[SKTexture textureWithImageNamed:@"spacecat_1"]];
_tapAction = [SKAction animateWithTextures:spaceCatTextures timePerFrame:0.25];
return _tapAction;
}
Question Two. Why do I not have to put an Asterisk in the CGPoint variable found in the for in loop ?
for (UITouch *touch in touches) {
CGPoint position = [touch locationInNode:self];
[self shootProjectileAtPosition:position];
3 Answers
Sebastien Thomas
16,502 PointsCheck out Douglas Turner's excellent Objective-C Basics course here on Treehouse (https://teamtreehouse.com/library/objectivec-basics/pointers-and-memory/pointer-power)
He explains it way better than I could in just a few lines in a forum.
Also, Pasan Premaratne and Amit Bijlani have very thorough and well-explained video courses.
All the best with your learning :)
Sebastien Thomas
16,502 PointsHi Shaun,
An asterisk in Objective-C indicates a pointer to an object, i-e. an address to where the object is in memory.
CGPoint is not an object, it is a struct and structs do not take pointers.
Hope this helps
Shaun Kelly
5,648 PointsCould you describe what an object is ?