Can you return two arguments in objective
Just wondering if you can return two arguments in an objective c method, for example I'd like to return a cartesian coordinate (x,y), basically two ints. is the only way to do this by creating a class and returning an instance? Is there some other way I'm not thinking of, kind of a beginner here.
(Syntactical help would also be appreciated.)
Thanks,
Nick
You can only return one value from a function (just like C), but the value can be anything, including a struct. And since you can return a struct by value, you can define a function like this (to borrow your example):
-(NSPoint)scalePoint:(NSPoint)pt by:(float)scale
{
return NSMakePoint(pt.x*scale, pt.y*scale);
}
This is only really appropriate for small/simple structs.
If you want to return more than one new object, your function should take pointers to the object pointer, thus:
-(void)mungeFirst:(NSString**)stringOne andSecond:(NSString**)stringTwo
{
*stringOne = [NSString stringWithString:@"foo"];
*stringTwo = [NSString stringWithString:@"baz"];
}
You can either return one value directly and return another by reference, as shown in gs's answer, or create a struct type and return that. For example, Cocoa already includes a type to identify points on a 2D plane, NSPoint.
你不能为此做一个NSArray
吗?
return [NSArray arrayWithObjects:coorX, coorY, nil];
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