Welcome to the Code-Alongs section! Here you'll find interactive exercises to practice your JavaScript skills. You can write and run code directly in your browser.
In this exercise, you'll practice declaring variables and using console.log() to output information.
Remember to use let or const to declare variables. When printing multiple values, you can use template literals with backticks (`) to create more readable output.
// Declare variables to store your name, age, and favorite programming language
const name = "Alex Johnson";
let age = 25;
const favLanguage = "JavaScript";
// Using regular string concatenation
console.log("My name is " + name + ", I am " + age + " years old, and my favorite programming language is " + favLanguage + ".");
// Using template literals (preferred method)
console.log(`My name is ${name}, I am ${age} years old, and my favorite programming language is ${favLanguage}.`);
// Next year, my age will increase
age = age + 1;
console.log(`Next year, I will be ${age} years old.`);
Practice using if/else statements to make decisions in your code.
Remember to use the if/else structure for conditional logic. You can test your code with different age values.
// Create a voting eligibility checker
const voterAge = 17; // Change this value to test different ages
if (voterAge >= 18) {
console.log("You are " + voterAge + " years old.");
console.log("You are eligible to vote!");
} else {
console.log("You are " + voterAge + " years old.");
console.log("Sorry, you must be 18 or older to vote.");
console.log("You can vote in " + (18 - voterAge) + " years.");
}
// Testing with another age example
const anotherAge = 21;
const canVote = anotherAge >= 18;
if (canVote) {
console.log(`At ${anotherAge} years old, you can vote!`);
} else {
console.log(`At ${anotherAge} years old, you cannot vote yet.`);
}
Practice creating and calling functions to organize your code.
A function should take width and height parameters, multiply them, and return the result. Don't forget to call your function with different values to test it.
// Function to calculate the area of a rectangle
function calculateRectangleArea(width, height) {
const area = width * height;
return area;
}
// Calculate area of first rectangle
const width1 = 5;
const height1 = 10;
const area1 = calculateRectangleArea(width1, height1);
console.log(`A rectangle with width ${width1} and height ${height1} has an area of ${area1} square units.`);
// Calculate area of second rectangle
const width2 = 7;
const height2 = 3;
const area2 = calculateRectangleArea(width2, height2);
console.log(`A rectangle with width ${width2} and height ${height2} has an area of ${area2} square units.`);
// Using the function with direct values
console.log(`A rectangle with width 4 and height 4 has an area of ${calculateRectangleArea(4, 4)} square units.`);
// Optional: Using arrow function
const calcArea = (w, h) => w * h;
console.log(`Using arrow function: Area = ${calcArea(6, 8)} square units.`);
Practice using loops to execute code multiple times.
You can use a for loop with a counter variable that increments/decrements on each iteration. Remember to use console.log() to see the output.
// Counting up from 1 to 10
console.log("Counting up:");
for (let i = 1; i <= 10; i++) {
console.log(i);
}
// Counting down from 10 to 1
console.log("\nCounting down:");
for (let i = 10; i >= 1; i--) {
console.log(i);
}
// Bonus: Using a while loop
console.log("\nUsing a while loop to count up:");
let counter = 1;
while (counter <= 10) {
console.log(counter);
counter++;
}
// Bonus: Skip even numbers
console.log("\nOnly odd numbers:");
for (let i = 1; i <= 10; i++) {
if (i % 2 === 0) {
continue; // Skip even numbers
}
console.log(i);
}