JavaScript is always pass by value, except when you are working with object that is pass by reference. In JS objects are not like in other languages. An object is a collection of properties, for example an array is an object too.

So, how do we copy objects straightforward? There are 2 basic options depending of the object depth.

A) Shallow copy where all nested objects are still copied as reference, so any change in those nested objects in obj_B will change obj_A.

const obj_B  = {...obj_A}
const arr_B  = [...arr_A]

B) Deep copy where the two objects will be completely different even with nested objects.

const obj_B  = JSON.parse(JSON.stringify(obj_A))

To know more check MDN Web Docs.