Java 22.1

Question

Can anyone help me debug this code, please?
https://www.sololearn.com/learning/1068

import java.util.Scanner;

public static void main (String[] args) {
Scanner sc = new Scanner (system.in)
int size = sc.nextInt(); // State the length of the array.
int[] nums = new int[size]; // Set the length of the array nums to the var size.
int sum = 0;
for (int i = 0; i < size; i++) {
nums[i] = sc.nextInt();

if (i % 4 == 0) {
sum += nums[i];
}
}System.out.println(sum);
sc.close();
}
}

I have put this code in Eclipse and debugged it. For some reason, it is missing 16 but including 7 in the first test so outputting 11 and missing 4 but including 32 in the second test so outputting 32.
Does anyone have any ideas where I've gone wrong?

Answer 1

Emma

You have created an object of Scanner class which is 'sc' but you used Scanner and scanner to read inputs which is wrong. There should be sc.nextInt() inside and outside the loop.

Also you did i % 4 which is wrong there should be num[i] % 4

Also there is System.in not system.in
System is a class so name should start from Capital letter.

Also you missed Semicolon after creating object of Scanner class.

Here is right solution:

import java.util.Scanner;

class Program {
public static void main (String[] args) {
Scanner sc = new Scanner(System.in);
int size = sc.nextInt(); // State the length of the array.
int[] nums = new int[size]; // Set the length of the array nums to the var size.
int sum = 0;

for (int i = 0; i < size; i++) {
nums[i] = sc.nextInt();

if (nums[i] % 4 == 0) {
sum += nums[i];
}
}

System.out.println(sum);
sc.close();
}

}

Answer 2

Thank you so much @AJ - SoloHelper. The Scanner issues were caused when copying the code across. It was the nums[] that fixed it. :)

Answer 3

Emma

Check my previous answer again. I have also provided solution.

Answer 4

I think the problem is
if(i%4==0)

If i were to create an array of length 5, then the iterations will be
0, 1, 2, 3, 4

So, you enter 5 numbers, but this is what happens

0%4 ==0 -> TRUE
1%4 ==0 -> FALSE
2%4 ==0 -> FALSE
3%4 ==0 -> FALSE
4%4 ==0 -> TRUE

Only the number associated with iteration 0 & iteration 4 will be added to your sum variable