Question

I know that there are 6 data types in JavaScript.

What are the “reference” types in JavaScript and what are the “value” data types in JavaScript?. Could someone list them by these 2 categories?

Answer 1

undefined, null, number, string, boolean and object of which only object is a “reference” type.

There is no assignment by reference or pass by reference in javascript, whenever you pass/assign a “reference” type, you pass/assign a copy of the reference, you don’t create a reference of the reference which would have different implications.

You can use these functions:

function isReferenceType( value ) {
     return Object(value) === value;
}

function isPrimitiveType( value ) {
     return Object(value) !== value;
}