findSumOfDigits()

Step 1: Understand the Problem

The first step when solving any programming problem is understanding the problem. Our function, findSumOfDigits, will accept an integer as input. The function needs to return the sum of the digits in the input number.

For instance, if our function receives 123, it should output 6 as 1 + 2 + 3 = 6. Similarly, for input number 4567, the function should return 22 i.e. 4 + 5 + 6 + 7 = 22.

Now that we understand the problem we're attempting to solve, let's move to the implementation.

Step 2: Initialize the Function

First, we must declare our function, which we're going to call findSumOfDigits. This function will take an integer number as its argument.

public class Main { 
    public static int findSumOfDigits(int number) { 
    }
}

Step 3: Implementation of the Logic

In this step, we'll implement the logic to find the sum of the digits. We will use the modulus operator (%) to extract each digit from the number and add it to the sum. This process will continue until the number becomes 0.

public static int findSumOfDigits(int number) { 
    int sum = 0; 
    while (number != 0) { 
        sum = sum + number % 10; 
        number = number / 10; 
    } 
    return sum; 
}

Step 4: Testing the Function

Let's now test our findSumOfDigits function with a few test cases to ensure it's working as expected.

public static void main(String[] args) { 
    System.out.println(findSumOfDigits(123)); 
    System.out.println(findSumOfDigits(4567)); 
}

Conclusion

In conclusion, we have successfully built our findSumOfDigits function. It accepts an integer as input and returns the sum of its digits. Our function is successfully solving the problem as desired.