Learn JavaScript Fundamentals: Variables, Operators, and More
Learn the basics of JavaScript programming, including variables, operators, control structures, functions, and more.
1. Question: Write a simple program in JavaScript to calculate the area of a rectangle.
Take inputs for length and width, and output the result.
// Program to calculate area of a rectangle
const length = 10; // Length of the rectangle
const width = 5; // Width of the rectangle
const area = length * width; // Formula for area
console.log("The area of the rectangle is:", area);
2. Question: Write a program that takes a user's name as input, stores it in a variable, and prints a greeting message. Add comments to explain each step.
// Declare a variable to store the user's name
const userName = "Alice"; // Example name
// Print a greeting message
console.log("Hello, " + userName + "! Welcome to JavaScript.");
3. Question: Write a program that demonstrates the difference between const, let, and var. Show how re-assignment works and where it doesn't.
// Using const - value cannot be reassigned
const pi = 3.14;
// pi = 3.1415; // This will throw an error
// Using let - value can be reassigned
let age = 25;
age = 26; // Re-assignment works
// Using var - value can also be reassigned
var color = "red";
color = "blue"; // Re-assignment works
console.log("Const example:", pi);
console.log("Let example:", age);
console.log("Var example:", color);
4. Question: Write a program to demonstrate the difference between a primitive type and an object in JavaScript.
// Primitive type example
let primitiveValue = 10;
let anotherValue = primitiveValue; // Copy the value
anotherValue = 20; // Change the copied value
console.log("Primitive Value:", primitiveValue); // Output: 10
// Object example
let objectValue = { name: "Alice" };
let anotherObject = objectValue; // Reference the same object
anotherObject.name = "Bob"; // Modify the object
console.log("Object Value:", objectValue); // Output: { name: "Bob" }
5. Question: Write a program to take two numbers as input and use different operators to calculate and print the results for: Addition, Subtraction, Multiplication, Division and Modulus.
// Inputs
const num1 = 20;
const num2 = 5;
// Performing operations
console.log("Addition:", num1 + num2); // Output: 25
console.log("Subtraction:", num1 - num2); // Output: 15
console.log("Multiplication:", num1 * num2); // Output: 100
console.log("Division:", num1 / num2); // Output: 4
console.log("Modulus:", num1 % num2); // Output: 0