flw2-u1l4-23-24-student-exercises's Introduction

Lesson 1.4: Arrays & Objects

📌 Key Concepts:

Definition: An array is a data structure in JavaScript used to store multiple values in a single variable.
```
let fruits = ["apple", "banana", "cherry"];
```
Index: Each item in an array is assigned a number starting from 0, which is called its index.
```
fruits[0];  // "apple"
```
Length: You can find out how many items are in an array with .length.
```
fruits.length;  // 3
```
Array Methods:
- .push(): Add an element to the end.
- .pop(): Remove the last element.
- .join(): Combine all elements into a string.
- .splice(): Add or remove elements from the array.
```
fruits.push("grape");  // Adds "grape" to the end
fruits.pop();          // Removes the last item ("grape")
```

Definition: Objects are collections of key-value pairs. They help associate different values together.
```
let book = {
  title: "Harry Potter",
  author: "J.K. Rowling",
  published: 1997
};
```
Properties: The keys in an object (like title, author, etc. in the above example) are called properties.
Accessing Values: Use dot notation to access values in an object.
```
book.title;  // "Harry Potter"
```

Arrays in Objects: Objects can hold arrays as values.

let student = {
  name: "Alice",
  subjects: ["Math", "Science", "English"]
};
student.subjects[1];  // "Science"

Arrays are ordered lists, and you can access any element by its index.
Objects store data as key-value pairs and are great for representing entities with various attributes.
Always use the right data structure for your needs; sometimes, you might even use arrays and objects together!

Always comment your code! It helps in understanding what each part of the code does.
```
// This is a single line comment in JavaScript
```
If you're unsure about a method or property, search online or revisit this README.

Happy coding!

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