How do you make a button only send one input to a source while being pushed down and not send another one until the button is let go and repressed? - variables

Question

In a basic variable and Button setup on an Arduino software, the idea is that if you press a button, you gain one on a variable. Theoretically, holding the button shouldn't cause the variable to increase more than one until the release and repressing of the button. However, I could not make this happen. How is this supposed to be done?
I tried using an else around a delay (because the adding one to a variable code was inside an "if" statement) so it would not delay unless the button and released and would not count multiple button inputs, but this resulted in a larger increase when a button was clicked rather than just a one increase.
const int buttonPin = 8;
int number = 0;
int numbertwo = 0;
int buttonState = 0;
void setup()
{
pinMode(buttonPin, INPUT);
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW){
numbertwo = ++number;
delay(100);
}
(Can use any method to determine variable, like on an LCD)
As mentioned above, I expected the variable to only increase by one when a button is pressed and not to continue increasing until the button is released and re-pressed, but what actually happened was the variable kept increasing in value as the button was held.

Answer 1

I'm assuming you want the variable "number" increase by 1 per press. I think you are looking for something like this:
const int buttonPin = 8;
int number = 0;
int buttonState = 0;
void setup() {
pinMode(buttonPin, INPUT);
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW){
++number;
// This loop is to make sure not to count up until button is released
do {
delay(5);
buttonState = digitalRead(buttonPin);
} while (buttonState == LOW);
}
}
If you don't like the loop based implementation, here's a state based implementation for you:
const int buttonPin = 8;
int number = 0;
int buttonState = 0;
int prevState = -1;
void setup() {
pinMode(buttonPin, INPUT);
prevState = -1;
}
void loop()
{
buttonState = digitalRead(buttonPin);
if (buttonState == LOW && prevState != buttonState){
++number;
prevState = buttonState;
}
delay(5);
}