Welcome to the recap of our lesson on JavaScript functions! This README is your handy reference guide. Whenever you need a quick refresher, pop in here.

• A function in JavaScript is a block of reusable code that performs a specific task.
• Functions are like recipes: they take inputs, process them, and return an output.

function functionName(parameters) {
  // Body of the function
}

• Function Name: A unique name to identify and call the function.
• Parameters (optional): Inputs you provide to a function. They're placed inside parentheses.
• Function Body: Enclosed by {}. This is where the magic happens; it contains statements that define what the function does.

function greet(name) {
  console.log("Hello, " + name);
}

• To execute a function, you call it by its name followed by parentheses.

greet("Alice");  // Outputs: Hello, Alice

• Parameters: Are names listed in the function definition. They are placeholders.
• Arguments: Are the real values passed to the function when you call it.

function multiply(x, y) {
  return x * y;
}

multiply(2, 3);  // Here, 2 and 3 are arguments.

• Avoid Repetition: Reusable pieces of code mean you don't have to rewrite the same logic.
• Organize Code: Makes code cleaner, more readable, and maintainable.
• Modularity: Break down complex problems into smaller, manageable chunks.

// WITHOUT Functions
let name1 = "Matt";
console.log("hi " + name1 + ", how are you");

let name2 = "Joe";
console.log("hi " + name2 + ", how are you");

// WITH Functions
function sayHello(name){
  console.log("hi " + name + ", how are you");
}

sayHello("Matt");
sayHello("Joe");

• Special functions that respond to user interactions/events, making web pages interactive.

let button = document.querySelector("button");
button.addEventListener('click', function() {
  alert('Button was clicked!');
});

• Functions are fundamental in JavaScript for organizing and reusing code.
• They can take inputs (parameters) and return outputs.
• Event handlers are functions that respond to user actions.

Happy coding!