Primitive Types and Operations

JavaScript has several primitive types - these are the basic building blocks for all data in your programs.

Three Essential Primitives

Number

Numbers represent any numeric value - whole numbers, decimals, negative numbers, and special numeric values.

Copy-10
25
19.99
0
Infinity

String

Strings represent text data - any sequence of characters enclosed in quotes.

Copy'Sarah'
"Hello, world!"
''
""

• Can be created with single or double quotes
• Can be empty (just quotes with nothing inside)

Boolean

Booleans represent true/false values.

Copytrue
false

Basic Operations on Primitives

Operations are actions you can perform with primitive values. Each type supports different operations.

Number Operations

• Arithmetic Operations

  Copy// Basic math
  10 + 3 // 13
  10 - 3 // 7
  10 * 3 // 30
  10 / 3 // 3.333...
  
  // Order of operations applies
  2 + 3 * 4 // 14 (not 20)
  (2 + 3) * 4 // 20
  

• Comparison Operations

  Copy85 == 92 // false
  85 != 92 // true
  
  85 < 92 // true
  85 > 92 // false
  85 <= 85 // true
  92 >= 90 // true
  

String Operations

• Concatenation (Joining Strings)

  Copy"Kyle" + " " + "Cook" // "Kyle Cook"
  

• String Comparison

  Copy"apple" == "apple" // true
  "apple" != "apple" // false
  
  // Alphabetical comparison
  "apple" < "banana" // true ("apple" comes before "banana")
  

Boolean Operations

• Logical Operations

  Copytrue && false // false (AND)
  true || false // true (OR)
  !true // false (NOT)
  

• Boolean Comparison

  Copytrue == true // true
  true == false // false
  true != false // true
  

Determining Types

You can check the type of any value using the typeof operator:

Copytypeof 42 // "number"
typeof "Hello" // "string"
typeof true // "boolean"

typeof 1 == typeof 2 // true