Functions in JavaScript

Introduction: Link to heading

Functions are reusable blocks of code that perform a specific task. They are an essential tool for writing efficient and organized JavaScript code.

Types of functions Link to heading

Declaratives: They are defined using the function keyword.
Expression: They are defined as an expression that is assigned to a variable.

Examples Link to heading

Declaratives: Link to heading

// Function declaration
function myFunction() {
    // Function code
    return 3;
}
// Function call
myFunction();

Expression: Link to heading

// Declaration of the function as an expression
var myFunction = function(a, b) {
    // Function code
    return a + b;
};
// Function call
myFunction(1, 2);

Getting results Link to heading

Browser Console: console.log() can be used to print the value of a variable or expression to the browser console.
Return: The function can return a value using the return keyword.

Examples Link to heading

Browser console Link to heading

function greetStudents(student) {
    console.log(student);
}

greetStudents("John"); // Print "John" to the console

Return: Link to heading

function add(a, b) {
    var result = a + b;
    return result;
}

var sum = add(1, 2); // The variable `sum` stores the result of the function, which is 3

More examples: Link to heading

// Function that calculates the area of a square
function squareArea(side) {
return side \* side;
}

var area = squareArea(5); // The variable `area` stores the area of the square, which is 25

// Function that checks if a number is even
function isEven(number) {
    return number % 2 === 0;
}

var isEven = isEven(10); // The variable `isEven` stores `true` because 10 is an even number

// Function that greets a user
function greetUser(name) {
return `Hello ${name}, how are you?`;
}

var greeting = greetUser("Diego"); // The variable `greeting` stores the message "Hello Diego, how are you?"

Tips for using functions: Link to heading

Use descriptive names for functions.
Break your code into small, manageable functions.
Document your features with comments.
Reuse functions whenever possible.

Keep learning about functions in JavaScript to improve your programming skills!

Take advantage of understanding functions to write more modular and effective JavaScript code!