Variable number of arguments in Objective-C methods

Ever wondered how the NSString's +stringWithFormat: method work? How you can pass endless arguments in it?
Well methods that take variable arguments are known as variadic methods.

Here is an example of such a method

Declare variable argument function in your .h file as below

- (void) appendObjects:(id) firstObject, ...; // This method takes a nil-terminated list of objects.

Here is the definition in .m file –

- (void) appendObjects:(id) firstObject, ...

{

     id eachObject;

     va_list argumentList;

     if (firstObject) // The first argument isn't part of the varargs list,

     {

           [self addObject: firstObject];// so we'll handle it separately.

           va_start(argumentList, firstObject); // Start scanning for arguments after firstObject.

           while (eachObject = va_arg(argumentList, id)) // As many times as we can get an argument of type "id"

           {

               [self addObject: eachObject]; // that isn't nil, add it to self's contents.

           }

           va_end(argumentList); 

     }

}

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