Lesson 13 - Overloading operators and other useful syntax in Swift

In the previous lesson, Type casting and object hierarchy in Swift, we talked about interfaces.

While the previous lessons may have been considered necessary for you to actually create something in Swift, this is rather a complementary lesson and you could even skip it. On the other hand, it's not long and knowing about these options might be useful for you.

Operator overloading

You have for sure encountered operators such as +, - or * in programming. We use them to perform numerical math operations. Under the hood, operators are special functions. They are defined for numbers, but we can easily define them for any of our custom type (i.e. structure or class). It's simply a method whose name is the given operator.

This may sometimes be useful. However, you can, of course, name the method as e.g. add() sum up two instances in it and return the result, avoiding using the + operator at all.

As an example, we can use a Point struct, which represents a point in the 2D space with x and y coordinates. The struct declaration looks as follows:

struct Point {
    var x: Int
    var y: Int
}

When frequently used, it would make sense to create an operator for adding two points. Even using this syntax will be more clear. Therefore, we'll declare the + operator to the point as its static method:

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