I am pretty new to JavaScript. I have a NodeJS express app which creates an array of instances of a class. I want to provide a client with a handle to an instance so that the server does not have to find the instance by ID for every API call. The array index may change as instances are deleted. Is there a clean way of doing this?
Instead of using an array, consider using a Map or object, for which key lookup is sublinear (and much faster than using findIndex with an array). For example, rather than
const handles = [];
// when you need to add an item:
handles.push(new Handle(1234));
// when you need to retrieve an item:
const handle = handles.find(obj => obj.id === id)
// will be undefined if no such handle exists yet
do
const handles = new Map();
// when you need to add an item:
handles.set(1234, new Handle(1234));
// when you need to retrieve an item
const handle = handles.get(id);
// will be undefined if no such handle exists yet
There's no need to worry about re-indexing with this approach either.