How Complex Values Are Stored/Copied in JavaScript

It is extremely important to grok that complex values are stored and manipulated by reference. When creating a variable containing a complex object, the value is stored in memory at an address. When you reference a complex object, you’re using its name (i.e., variable or object property) to retrieve the value at that address in memory. The implications are significant when you consider what happens when you attempt to copy a complex value. Below, we create an object stored in the variable myObject. Then the value in myObject is copied to the variable copyOfMyObject. Really, it is not a copy of the object—more like a copy of the address of the object.