iphone - Converting NSData to int

Question

I've an NSData object, the length is 4 bytes .These four bytes i'm extracting from another NSData object using ,

fourByteData=[completeData subdataWithRange:NSMakeRange(0, 16)];

My first question is, will the above statement provide me the first four bytes of complete data.

If Yes, then how to convert all these bytes to an equivalent int.

Answer 1

Is 268566528 the value you expect or perhaps you expect 528? If the correct value is 528 then the byte order is big-endian but the cpu is little-endian, the bytes need to be reversed.

So, if the correct value should be 528 then:

NSData *data4 = [completeData subdataWithRange:NSMakeRange(0, 4)];
int value = CFSwapInt32BigToHost(*(int*)([data4 bytes]));

Also note that network standard order is big-endian.