Hands-On Data Structures and Algorithms with JavaScript

Mark and sweep algorithm

Since there is no accurate way to determine whether the data at a particular memory location is going to be used or not in the future, we will need to depend on alternatives which can help us make this decision. In JavaScript, we use the concept of a reference to determine whether a variable is still being used or not—if not, it can be garbage collected.

The concept of mark and sweep is very straightforward: what all memory locations are reachable from all the known active memory locations? If something is not reachable, collect it, that is, free the memory. That's it, but what are the known active memory locations? It still needs a starting point, right? In most of the browsers, the GC algorithm keeps a list of the ...