How can I add one value to a variable?

Question

C++ / C#

public void OnClickBuy()
    {
        if(Money >= 100)
        {
            MoneyUp *= 2;
            Money -= 100;
            Repairs = 2;
        }

For example, how can I make it so that after clicking on the button, the value 1 is added to the "repair" variable?

Answer 1

after pressing the button, the value 1 was added to the "repair" variable

Repairs = Repairs + 1

Answer 2

Repairs++;