Common array operations in Java - Mini Project: Build & Apply

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Common array operations

📖 Scenario: You are working on a simple inventory system for a small store. The store keeps track of the quantities of three products in an array.

🎯 Goal: You will create an array to hold product quantities, set a threshold for low stock, find which products are low in stock, and print those products.

📋 What You'll Learn

Create an integer array called quantities with values 10, 5, and 2

Create an integer variable called lowStockThreshold and set it to 5

Use a for loop with variable i to find indices of products with quantity less than lowStockThreshold and store these indices in an integer list called lowStockProducts

Print the lowStockProducts list

💡 Why This Matters

🌍 Real World

Stores and warehouses often track product quantities to know when to reorder items.

💼 Career

Understanding arrays and loops is essential for managing collections of data in software development.

1

Create the product quantities array

Create an integer array called quantities with these exact values: 10, 5, and 2.

Java

# Create the integer array quantities with values 10, 5, and 2
// Your code here

💡 Need a hint?

Use curly braces to list the values inside the array.

2

Set the low stock threshold

Create an integer variable called lowStockThreshold and set it to 5.

Java

int[] quantities = {10, 5, 2};
// Create the integer variable lowStockThreshold and set it to 5
// Your code here

💡 Need a hint?

Use int to declare the variable and assign the value 5.

3

Find products with low stock

Create an ArrayList<Integer> called lowStockProducts. Then use a for loop with variable i from 0 to quantities.length - 1. Inside the loop, if quantities[i] is less than lowStockThreshold, add i to lowStockProducts.

Java

import java.util.ArrayList;

int[] quantities = {10, 5, 2};
int lowStockThreshold = 5;
// Create ArrayList lowStockProducts and add indices of low stock products
// Your code here

💡 Need a hint?

Remember to import java.util.ArrayList at the top.

4

Print the low stock product indices

Write a System.out.println statement to print the lowStockProducts list.

Java

import java.util.ArrayList;

int[] quantities = {10, 5, 2};
int lowStockThreshold = 5;
ArrayList lowStockProducts = new ArrayList();
for (int i = 0; i < quantities.length; i++) {
    if (quantities[i] < lowStockThreshold) {
        lowStockProducts.add(i);
    }
}
// Print the lowStockProducts list
// Your code here

💡 Need a hint?

The output should show the list of indices where the quantity is less than 5.