Understanding a constructor

Question

I have this piece of code :

public class Time2
{
    private int hour;
    private int minute;
    private int second;

    public Time2(int h = 0, int m = 0, int s = 0)
    {
        SetTime(h, m, s);
    }

    public Time2(Time2 time)
        : this(time.hour, time.Minute, time.Second) { }

    public void SetTime(int h, int m, int s)
    {
        Hour = h;
        Minute = m;
        Second = s;
    }

I understood everything except this part:

 public Time2(Time2 time)
            : this(time.hour, time.Minute, time.Second) { }

Can you tell me how this constructor works? The style and the job of the "this" keyword looks very unfamiliar to me. Thanks.

Answer 1

the this is calling another constructor on the class before executing the code of it's own function.

Try this: and look at the output in the console.

public Time2(int h = 0, int m = 0, int s = 0)
{
    Console.Log("this constructor is called");
    SetTime(h, m, s);
}

public Time2(Time2 time)
    : this(time.hour, time.Minute, time.Second) 
{
    Console.Log("and then this constructor is called after");
}