I learned about the Serial Monitor.
In the serial monitor you can see values. Today I learned how to change the value when clicking a button. Also how to turn it back to normal. So on the serial monitor it normally displays 1. But with the code I have written and with the circuit, when I click a switch the value changes to 0. And when I let go of the switch then it changes back to 1. And I did that with multiple switches. And that’s what I learned today.