What is the syntax for defining a function in JavaScript?

What is the syntax for defining a function in JavaScript?

In JavaScript, you can define a function using the following syntax:

function functionName(parameters) {
    // function body
}

You can also use arrow functions:

const functionName = (parameters) => {
    // function body
};

Can you give me an example of a function that adds two numbers?

Sure! Here's a simple function that adds two numbers:

function addNumbers(a, b) {
    return a + b;
}

You can call it like this: addNumbers(5, 3); // returns 8.

What are the differences between function declarations and function expressions?

Function declarations are hoisted, meaning they can be called before they are defined. For example:

console.log(myFunction()); // works
function myFunction() {
    return 'Hello!';
}

Function expressions, however, are not hoisted:

console.log(myFunction()); // TypeError: myFunction is not a function
var myFunction = function() {
    return 'Hello!';
};