Day 8: Cracking Numbers and Math in JavaScript

• Addition (+): Adds two numbers.
• Subtraction (-): Subtracts one number from another.
• Multiplication (): Multiplies two numbers.
• Division (/): Divides one number by another.
• Modulus (%): Returns the remainder of a division operation.
• Exponentiation (): Raises a number to a power.

let sum = 5 + 3; // 8
let difference = 10 - 4; // 6
let product = 2 * 7; // 14
let quotient = 15 / 3; // 5
let remainder = 10 % 3; // 1
let power = 2 * 3; // 8

JavaScript provides a built-in Math object that offers a wide range of mathematical functions and constants:

• Math.abs(x) : Returns the absolute value of x .
• Math.ceil(x) : Rounds x up to the nearest integer.
• Math.floor(x) : Rounds x down to the nearest integer.
• Math.max(x1, x2, ...) : Returns the largest of the given numbers.
• Math.min(x1, x2, ...) : Returns the smallest of the given numbers.
• Math.pow(x, y) : Raises x to the power of y .
• Math.round(x) : Rounds x to the nearest integer.
• Math.sqrt(x) : Returns the square root of x .
• Math.PI : Represents the mathematical constant pi (π).
• Math.E : Represents the mathematical constant e (Euler's number).

let absoluteValue = Math.abs(-5); // 5
let roundedNumber = Math.round(3.7); // 4
let maximum = Math.max(10, 25, 5); // 25
let squareRoot = Math.sqrt(16); // 4

You can convert strings to numbers using the parseInt() and parseFloat() functions.

let stringNumber = "123";
let integerNumber = parseInt(stringNumber); // 123
let floatNumber = parseFloat("3.14"); // 3.14

To format numbers for display, you can use the toFixed() method to control the number of decimal places:

let number = 3.14159;
let formattedNumber = number.toFixed(2); // "3.14"

Let's put our knowledge to use by calculating the area of a circle using JavaScript.

function calculateCircleArea(radius) {
let area = Math.PI * Math.pow(radius, 2);
return area;
}