Lesson 4: Arrays & Core Mutation Methods

Arrays are ordered list collections indexed starting at position 0.

push(item): Appends item to end.

pop(): Removes and returns the last item.

unshift(item): Inserts item at index 0.

shift(): Removes and returns the first item.

includes(item): Checks if an item exists in the array (returns boolean).

⊞HTML5 Web Code (index.html)

<!DOCTYPE html>

<head>

<title>JS Array Methods</title>

</head>

<h2>Tech Stack Array</h2>

const techStack = ["HTML5", "CSS3", "JavaScript"];

techStack.push("React");

techStack.push("Node.js");

document.getElementById("array-output").innerHTML =

"<strong>Items:</strong> " + techStack.join(" • ") + "<br>" +

"<strong>Total Technologies:</strong> " + techStack.length;

</script>

</body>

</html>