Question

I’m writing some library code, and users of the library sometimes have different opinions about which methods should use int and when to use NSNumber. I would like some way to set up a method so that either of

[myObject myMethod:5];

or

[myObject myMethod:[NSNumber numberWithInt:5]]

works the same way. In Java, autoboxing makes this relatively straightforward, but I’m not aware of any way to make this happen in objective-c. Is it possible to make this work?

Answer 1

Short answer: no.

Objective-C does not support function/method overloading, as in C++.

Usually, if you need to support different datatypes, you will create distinct methods.
Note that you can then convert yourself the passed value, so you don’t have to write (copy/paste) the same code.

For instance:

- ( void )methodWithInt: ( int )val
{
    [ self methodWithNumber: [ NSNumber numberWithInt: val ] ];
}

- ( void )methodWithLong: ( long )val
{
    [ self methodWithNumber: [ NSNumber numberWithLong: val ] ];
}

- ( void )methodWithNumber: ( NSNumber * )num
{
    /* Effective code */
}

At the end, everything will be redirected to the methodWithNumber method.