Objective-C how to convert a NSArray to Byte array?

Question

I'm not very experienced with objective-c and I would need to advise for the following use case:

I'm coding a React native module for ios and one of the native methods on the ios side receives an NSArray containing integers (each integer has a value between 0 and 255).

In my objective-c code, I need to convert this NSArray to a Byte bytes[] to pass it then to some SDK I use.

How can I do that conversion?

Andrey Chernukha · Accepted Answer · 2019-01-24 11:04:40Z

3

NSArray* array = @[@(1), @(5), @(115), @(34)];

Byte* bytes = calloc(array.count, sizeof(Byte));

[array enumerateObjectsUsingBlock:^(NSNumber* number, NSUInteger index, BOOL* stop){

    bytes[index] = number.integerValue;
}];

doWhateverWithBytes(bytes);
free(bytes);

assuming that doWhateverWithBytes accepts Byte bytes[]

edited Jan 24, 2019 at 11:04

answered Jan 24, 2019 at 10:21

Andrey Chernukha

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3 Comments

Żabojad Over a year ago

Thank you for your answer! sizeof(byte) gives Use of undeclared identifier 'byte'

Żabojad Over a year ago

Shouldn't it be the size of array instead?

Andrey Chernukha Over a year ago

The size of the array comes as the first parameter to calloc

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