Objective-C Programming: The Big Nerd Ranch Guide

More on blocks

Here are some other things you can do with blocks.

Return values

The block that you created for VowelMovement does not have a return value, but many blocks will. When a block returns a value, you can get the return value by calling the block variable like a function.

Let’s look again at one of the sample blocks you saw at the beginning of the chapter:

^(double dividend, double divisor) {
    double quotient = dividend / divisor;
    return quotient;
}

This block takes two doubles and returns a double. To store this block in a variable, you would declare a variable of that type and assign the block to it:

// Declare divBlock variable double (^divBlock)(double,double); // Assign block to variable divBlock = ...