Explore Basic Array Operations
In this step, you'll learn about common array operations in JavaScript. Open the arrays.js
file in the ~/project
directory and add the following code:
// Create an array of numbers
let numbers = [5, 2, 8, 1, 9, 3];
// Adding elements
numbers.push(10); // Add element to the end
numbers.unshift(0); // Add element to the beginning
console.log("After adding elements:", numbers);
// Removing elements
let lastNumber = numbers.pop(); // Remove last element
let firstNumber = numbers.shift(); // Remove first element
console.log("After removing elements:", numbers);
// Sorting the array
numbers.sort((a, b) => a - b); // Ascending order
console.log("Sorted array:", numbers);
// Reversing the array
numbers.reverse();
console.log("Reversed array:", numbers);
// Finding elements
let index = numbers.indexOf(8);
console.log("Index of 8:", index);
// Slicing the array
let slicedNumbers = numbers.slice(1, 4);
console.log("Sliced array:", slicedNumbers);
// Filtering the array
let evenNumbers = numbers.filter((num) => num % 2 === 0);
console.log("Even numbers:", evenNumbers);
// Mapping the array
let squaredNumbers = numbers.map((num) => num * num);
console.log("Squared numbers:", squaredNumbers);
When you run this code, you'll see the following example output:
After adding elements: [0, 5, 2, 8, 1, 9, 3, 10]
After removing elements: [5, 2, 8, 1, 9, 3, 10]
Sorted array: [1, 2, 3, 5, 8, 9, 10]
Reversed array: [10, 9, 8, 5, 3, 2, 1]
Index of 8: 2
Sliced array: [9, 8, 5]
Even numbers: [10, 8, 2]
Squared numbers: [100, 81, 64, 25, 9, 4, 1]
Key array operations demonstrated:
push()
and unshift()
to add elements
pop()
and shift()
to remove elements
sort()
to order elements
reverse()
to flip array order
indexOf()
to find element position
slice()
to extract a portion of an array
filter()
to create a new array with specific elements
map()
to transform array elements