Calculate Array Sum()

Step 1

First, we'will create a Java class and function signature. In our example we will create a class 'CalculateArraySum' and its function 'arraySum'. Our function will take one input parameter which is an array of integers.

public class CalculateArraySum {
    
    public int arraySum(int[] numbers){
    
    }
} 

Step 2

Now, inside our function we need to calculate the sum of all numbers in the array. First we will initialize a variable 'sum' to 0. We will use this variable to hold the total value as we go through each number in the array.

 public int arraySum(int[] numbers){
     int sum = 0;
 }

Step 3

Then, we will proceed to create a 'for' loop that will go through each number in the array. We start the loop index (i) at 0 because arrays in Java are zero-indexed which means the first item is at position 0.

 public int arraySum(int[] numbers){
     int sum = 0;
     for(int i = 0; i < numbers.length; i++){

     }
 }

Step 4

Inside the loop, we will add the current number to our sum variable using the += operator. This operator is shorthand for 'sum = sum + numbers[i]'

 public int arraySum(int[] numbers){
     int sum = 0;
     for(int i = 0; i < numbers.length; i++){
         sum += numbers[i];
     }
 }

Step 5

Lastly, we need to return the sum after we're done going through the entire array. We do this with the 'return' keyword.

 public class CalculateArraySum {
     public int arraySum(int[] numbers){
         int sum = 0;
         for(int i = 0; i < numbers.length; i++){
             sum += numbers[i];
         }
      return sum;
     }
 }

At the end of step 5, we have a complete Java function that calculates the sum of an array of integers. The user must input an array while calling the function, the function returns the sum of the array.