Primitive vs Reference

In JavaScript, a variable may store two types of values:

Primitives and Reference

7 Primitives (Data Types)

• Undefined:

  • Only one value, undefined.

• Null:

  • Only one value, null.

• Booleans:

  • Two values: true and false.

• Numbers:

  • One value for each floating point math number.

• BigInts:

  • One value for every conceivable integer.

• Strings:

  • One value for every conceivable string.

• Symbols:

  • More on this later

The size of a primitive value is fixed, therefore, JS stores the primitive value on the stack

Objects (Reference Type)

• One value for every object literal we execute

• A non-data type

• Structural Type

The size of a reference value is DYNAMIC so JS stores the reference value on the heap

Resource: https://www.javascripttutorial.net/javascript-primitive-vs-reference-values/

Functions

• One value for every function expression we execute.

• Structural Type