What is the purpose of initialization lists in C++ constructors?

What is the purpose of initialization lists in C++ constructors?

Initialization lists in C++ constructors allow you to initialize member variables before the constructor's body executes.

Can you give me an example of how to use an initialization list?

Sure! Here's a simple example:

class Point {
public:
    int x, y;
    Point(int xVal, int yVal) : x(xVal), y(yVal) {}
};

This initializes x and y using the values passed to the constructor.

Are there any advantages to using initialization lists over assignment in the constructor body?

Yes, using initialization lists can be more efficient, especially for const or reference members, which must be initialized directly.

What happens if I don't use an initialization list?

If you don't use an initialization list, member variables will be default-initialized first, and then assigned values in the constructor body, which can lead to unnecessary overhead.