Use Struct with NSMutableArray

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What’s the best way to put a c-struct in an NSArray?

How can I use struct inside NSMutableArray?

You can create an NSObject subclass that is, in essence, a struct, and use that subclass. — Hot Licks, Jan 28 '13 at 18:55

mattjgalloway · Answer 1 · 2013-01-28T19:07:21.347

You can't. All of the collections in Foundation can store only Objective-C objects. Since a struct is not an Objective-C object, it cannot be stored in there.

But you could wrap your struct into a simple NSObject subclass and store that in the array.

Or with NSValue:

#import <Foundation/Foundation.h>

struct TestStruct {
    int a;
    float b;
};

...

NSMutableArray *theArray = [NSMutableArray new];    

...

struct TestStruct *testStructIn = malloc(sizeof(struct TestStruct));
testStructIn->a = 10;
testStructIn->b = 3.14159;

NSValue *value = [NSValue valueWithBytes:testStructIn objCType:@encode(struct TestStruct)];
[theArray addObject:value];

free(testStructIn);

...

struct TestStruct testStructOut;
NSValue *value = [theArray objectAtIndex:0];
[value getValue:&testStructOut];

NSLog(@"a = %i, b = %.5f", testStructOut.a, testStructOut.b);

No real reason why one struct is heap allocated and one stack allocated, by the way. Just thought I'd do that to show it working.

@OneManCrew is correct. You can just wrap it in an NSValue. – jordanperry Jan 28 '13 at 19:00 — jordanperry, Jan 28 '13 at 19:00
Yeh you could use `NSValue`. – mattjgalloway Jan 28 '13 at 19:05 — mattjgalloway, Jan 28 '13 at 19:05

Use Struct with NSMutableArray

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