Adding until past 100 (while) · Java, before term starts

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Core exercise

Write sommeJusquaDepasser100() that adds 1 + 2 + 3 + … with a while loop, and returns the first sum that strictly exceeds 100.

Example · step-by-step trace · A while loop, iteration by iteration

We add 1 + 2 + 3 + … until the total exceeds 10. The condition is tested at the start of each iteration.

int somme = 0;
int n = 1;
while (somme <= 10) {
    somme += n;
    n++;
}
System.out.println(somme);

ligne	variables	sortie	explication
1	somme = 0		The accumulator starts at 0.
2	somme = 0, n = 1		n is the next number to add.
3	somme = 0, n = 1		Test: 0 ≤ 10? Yes → we enter the loop.
4	somme = 1, n = 1		somme += n: somme is 0 + 1 = 1.
5	somme = 1, n = 2		n becomes 2. Without this line, the loop would run forever.
3	somme = 1, n = 2		Test: 1 ≤ 10? Yes → second iteration.
4	somme = 3, n = 2		1 + 2 = 3.
5	somme = 3, n = 3		n becomes 3.
3	somme = 3, n = 3		Test: 3 ≤ 10? Yes → third iteration.
4	somme = 6, n = 3		3 + 3 = 6.
5	somme = 6, n = 4		n becomes 4.
3	somme = 6, n = 4		Test: 6 ≤ 10? Yes → fourth iteration.
4	somme = 10, n = 4		6 + 4 = 10. Careful: 10 ≤ 10 is still true!
5	somme = 10, n = 5		n becomes 5.
3	somme = 10, n = 5		Test: 10 ≤ 10? Yes → one more iteration. This is where the difference between ≤ and < comes into play.
4	somme = 15, n = 5		10 + 5 = 15.
5	somme = 15, n = 6		n becomes 6.
3	somme = 15, n = 6		Test: 15 ≤ 10? No → we leave the loop.
7	somme = 15, n = 6	`15`	The loop stopped at the first total that exceeds 10.

A workshop goes here: you write and run code in it. It requires JavaScript.

Starting code

Exercices.java

public class Exercices {

    public static void main(String[] args) {
        System.out.println(sommeJusquaDepasser100());
    }

    public static int sommeJusquaDepasser100() {
        // TODO : une boucle while
        return 0;
    }
}

The core exercise is validated in the workshop, which requires JavaScript.

Hint 1

Two variables: the sum and the next number to add. The loop continues as long as the sum is less than or equal to 100.