How to use .length in Javascript

For example:

// For an array
let fruits = ['apple', 'banana', 'cherry'];
console.log(fruits.length); // Output: 3

// For a string
let message = 'Hello, world!';
console.log(message.length); // Output: 13

In this examples, .length helps determine how many elements are in an array or how many characters are in a string.