Counting Up and Down

One of the easiest things to do with a for loop is count up to or down from a given number.

void main() {
// Goes from 1 to 100
for (int currentNumber = 1; currentNumber <= 100; currentNumber++) {
    System.out.println(currentNumber);
}

// Goes from 100 to 1
for (int currentNumber = 100; currentNumber >= 1; currentNumber--) {
    System.out.println(currentNumber);
}
}

You use the initializer to set some variable to a starting number like int currentNumber = 1, have the expression check if the number is at the target end number like currentNumber <= 100, and use the statement to change the number by one like currentNumber++.¹