Primitives

TypeScript supports primitives, which are the basic types in JavaScript that make up data other than functions and objects. TypeScript recognizes the following seven primitive types in JavaScript:

• bigint
• boolean
• null
• number
• string
• symbol
• undefined

If a value such as a parameter or variable is declared to be one of these, it is allowed to be assigned any of the literal values that are of that primitive type.

In this example, the variable decoration is initially declared to be type string. This means that decoration is allowed to be assigned, and reassigned, a plethora of string values:

let decoration: string;

decoration = 'Cobweb';
decoration = "Jack O'Lantern";
decoration = 'Lights';

In other words:

• A primitive is a basic type of data, such as number or string
• A literal is an example of a primitive with a value, such as 1337 or "ghost"