What is the JavaScript equivalent to a C# HashSet?

javascript jquery hashset

Jonathan Allen · Jun 13, 2014 · Viewed 69k times · Source

I have a list of a few thousand integer keys. The only thing I need to do with this list is say whether or not a given value is in the list.

For C# I would use a HashSet to make that look-up fast. What's the JavaScript equivalent?

Minimal support level: IE 9+, jQuery (current)

Answer

Actually JavaScript provides a Set object, fairly simple to use:

var set = new Set();
set.add(1);
set.add(2);

set.has(1)    // true

Unfortunately, it is not compatible with IE9.