How can I add CGPoint objects to an NSArray the easy way?

Question

I have about 50 CGPoint objects that describe something like a "path", and I want to add them to an NSArray. It's going to be a method that will just return the corresponding CGPoint for an given index. I don't want to create 50 variables like p1 = ...; p2 = ..., and so on. Is there an easy way that would let me to define those points "instantly" when initializing the NSArray with objects?

score 330 · Accepted Answer · answered May 22 '09 at 19:44

330

With UIKit Apple added support for CGPoint to NSValue, so you can do:

NSArray *points = [NSArray arrayWithObjects:
                     [NSValue valueWithCGPoint:CGPointMake(5.5, 6.6)],
                     [NSValue valueWithCGPoint:CGPointMake(7.7, 8.8)],
                     nil];

List as many [NSValue] instances as you have CGPoint, and end the list in nil. All objects in this structure are auto-released.

On the flip side, when you're pulling the values out of the array:

NSValue *val = [points objectAtIndex:0];
CGPoint p = [val CGPointValue];

answered May 22 '09 at 19:44

Jarret Hardie

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For scalar types, have a look at NSNumber... you'll see constructors like numberWithBool: numberWithInteger: numberWithFloat:, numberWithUnsignedShort:, etc. – Jarret Hardie May 22 '09 at 20:07
5

Alternatively you can use NSValue directly: [NSValue valueWithBytes: &someStructSockaddr objCType: @encode(struct sockaddr)] for instance. – Jim Dovey May 23 '09 at 01:42
In my case CGPoint p = [val CGPointValue]; did not work. However CGPoint p = [val pointValue]; did work. – Bob Ueland Aug 10 '22 at 10:44

score 7 · Answer 2 · answered May 06 '14 at 02:22

7

I use this:

Create array:

NSArray *myArray = @[[NSValue valueWithCGPoint:CGPointMake(30.0, 150.0)],[NSValue valueWithCGPoint:CGPointMake(41.67, 145.19)]];

Get 1st CGPoint object:

CGPoint myPoint = [myArray[0] CGPointValue];

answered May 06 '14 at 02:22

Tibidabo

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GilesDMiddleton · Answer 3 · 2018-09-16T11:36:19.187

4

You can also write this in a minimal form of:

CGPoint myArray[] = { CGPointMake(5.5, 6.6), CGPointMake(7.7, 8.8) };

CGPoint p2 = myArray[1];

edited Sep 16 '18 at 11:36

answered May 31 '15 at 12:42

GilesDMiddleton

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score 2 · Answer 4 · answered May 22 '09 at 19:44

2

Have you taken a look at CFMutableArray? That might work better for you.

answered May 22 '09 at 19:44

Ramin

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How can I add CGPoint objects to an NSArray the easy way?

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