Question:

Consider a program that tracks the sales of various products in different regions. The data is stored in a multidimensional array where the rows represent the regions and the columns represent the products. Each entry in the array represents the number of units sold for a specific product in a specific region.

Write a method named getTotalSales that takes in a multidimensional array and returns the total number of units sold across all regions and products.

The method signature is:

public static int getTotalSales(int[][] salesData)

For example, given the following salesData array:

int[][] salesData = {
    {4, 7, 2},
    {3, 5, 9},
    {8, 1, 6}
};

The getTotalSales method should return 45 since the total number of units sold is 45.

Provide your implementation of the getTotalSales method, and explain your approach in detail.

Answer:

public class MultidimensionalArrayExample {

    public static void main(String[] args) {
        int[][] salesData = {
            {4, 7, 2},
            {3, 5, 9},
            {8, 1, 6}
        };
        
        int totalSales = getTotalSales(salesData);
        System.out.println("Total sales: " + totalSales);
    }
    
    public static int getTotalSales(int[][] salesData) {
        int total = 0;
        
        // Iterate through each row (region)
        for (int row = 0; row < salesData.length; row++) {
            // Iterate through each column (product)
            for (int col = 0; col < salesData[row].length; col++) {
                // Add the value in the current cell to the total
                total += salesData[row][col];
            }
        }
        
        return total;
    }
}

Explanation:

• The getTotalSales method takes in a multidimensional array salesData as a parameter and returns the total number of units sold across all regions and products.
• We initialize a variable total to keep track of the cumulative sales.
• We use nested for loops to iterate through each cell in the salesData array.
  • The outer loop iterates through each row (region) using the variable row.
  • The inner loop iterates through each column (product) within the current row using the variable col.
• For each cell, we add the value in the current cell (salesData[row][col]) to the total variable.
• Finally, we return the total value, which represents the total number of units sold.

In the given example, the salesData array is:

int[][] salesData = {
    {4, 7, 2},
    {3, 5, 9},
    {8, 1, 6}
};

The nested for loops iterate through each cell of the array:

• In the first iteration, row is 0 and col is 0, so the value 4 is added to the total.
• In the second iteration, row is 0 and col is 1, so the value 7 is added to the total.
• In the third iteration, row is 0 and col is 2, so the value 2 is added to the total.
• The process continues for each cell in the array.
• After traversing all cells, the total value becomes 45, representing the total number of units sold.
• The program then prints "Total sales: 45" to the console.