How can I create an empty array in objective C, and assign value into it one by one?

NSMutableArray* abc = [NSMutableArray array];
for (int i = 0; i < 10; ++ i)
   [abc addObject:[NSNumber numberWithInt:i]];
return abc;

Here,

• NSMutableArray is a "mutable" array type. There is also a constant array super-type NSArray. Unlike C++, ObjC's array is not typed. You can store any ObjC objects in an NSArray.
• -addObject: appends an ObjC at the end of the array.
• Since NSArrays can only store ObjC, you have to "box" the integer into an NSNumber first.

This is actually more similar to the C++ code

std::vector<int> abc;
for (int i = 0; i < 10; ++ i)
   abc.push_back(i);
return abc;