variables and datatypes in js javascript series 2024

javascript variables and data types: a comprehensive tutorial

javascript is a versatile programming language that is widely used for web development. understanding variables and data types is crucial for any developer, as they form the foundation of programming logic. in this tutorial, we will explore the concepts of variables and data types in javascript, complete with code examples.

1. what are variables?

variables are containers that store data values. in javascript, you can declare variables using the `var`, `let`, or `const` keywords.

declaring variables

1. **`var`**: the traditional way to declare a variable. it has function scope or global scope.
2. **`let`**: introduced in es6 (ecmascript 2015), `let` allows you to declare block-scoped variables.
3. **`const`**: also introduced in es6, `const` is used to declare block-scoped variables that cannot be reassigned.

example of variable declaration

2. javascript data types

javascript has several built-in data types that can be categorized into two groups: **primitive** and **reference** types.

2.1 primitive data types

primitive data types are the most basic data types in javascript. they include:

1. **string**: represents a sequence of characters.
- example: `"hello, world!"`
2. **number**: represents both integer and floating-point numbers.
- example: `42`, `3.14`
3. **boolean**: represents a logical entity and can have two values: `true` or `false`.
4. **undefined**: a variable that has been declared but has not yet been assigned a value.
5. **null**: represents an intentional absence of any object value.
6. **symbol**: introduced in es6, represents a unique and immutable value.
7. **bigint**: represents whole numbers larger than 2^53 - 1.

example of primitive data types

2.2 reference data types

reference data types are more complex and can store collections of values. they include:

1. **object**: a collection of key-value pairs.
2. **array**: a special type of object for storing ...

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variables
datatypes
javascript
js
data types
variable declaration
let
const
var
primitive types
reference types
type coercion
dynamic typing
data structures
scope