[FIXED] What is happening in this array?

Issue

I'm reviewing arrays and for loops among other things in my computer science course. One of the examples used was the code below. After being run, the array displays 2, 3, 4, 2. How is this?

    int[] numbers = {1, 2, 3, 4};

    for (int i = 0; i < numbers.length; i++) {
        numbers[i] = numbers[(i+1) % numbers.length];
    }
    System.out.println(numbers);

Solution

An important concept in understanding the code you are looking it, especially the block inside the for loop, is the modulus operator (%) also known as the remainder operator. When applied, the % operator returns the remainder of two numbers.

Hence, the computation:

(i+1) % numbers.length

will always return a remainder.

Walking through it with a debugger (or print statements as suggested) while evaluating the values (and operations) at each iteration is a great way of understanding it.

You can also read more about it: https://www.baeldung.com/modulo-java

Answered By - k.wahome