I have a float pointer and want to return it from class, is this the right way?

• (float *)amb { float ret[4] = {x, y, z, w}; return ret; }

//Another file

float test[4] = [AClass amb];

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It’s the right way to return a pointer, but your code is because your array will be deallocated when amb returns (it goes out of scope). Try this:

• (float )amb { float ret = calloc(sizeof(float),4); ret[0] = x; ret[1] = y; ret[2] = z; ret[3] = w; return ret; }

//Another file

float* test = [AClass amb];

Don’t forget to call free(test) when you’re done.

Alternatively, you could use an NSArray of NSNumbers.

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Another way would be to make the caller take care of memory allocation:

• (void)getAmb:(float *)array { array[0] = x; array[1] = y; array[2] = z; array[3] = w; }

// call it like this:

float test[4]; [obj getAmb:test];

this way would be more in keeping with Cocoa semantics

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Since this is obviously a 4-vector, I’d do it like this:

typedef struct { float x, y, z, w; } V4;

-(V4)getAmb { V4 ret={x, y, z, w}; return ret; }

Of course, that wouldn’t be a pointer return.

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You could even wrap that 4-vector up in an ObjC class if you wanted.

@interface fourVector : NSObject { float x, y, z, w; }

• (id)initWithX:(float)_x y:(float)_y z:(float)_z w:(float)_w;
• (float)getX;
• (float)getY;
• (float)getZ;
• (float)getW; @end

That way, you can take advantage not only of adding transformations, etc., to the interface, you can use ObjC’s MemoryManagement to solve the return problem:

-(fourVector*)getAmb { return [[[fourVector alloc] initWithX:x y:y z:z w:w] autorelease]; }

Indeed, you could simply store a fourVector in the class providing getAmb, instead of x,y,z and w. You could then give it a better name.