Maps and Sets
Unique Values
Use a Set to count distinct values.
Unique Values
set_unique.js
const color = "red";
const uniqueCount = new Set([color, "blue", color, "red"]).size;
console.log("color=" + color);
console.log("unique=" + uniqueCount);
set-unique
A `Set` keeps only one copy of each value. Its `.size` tells you how many distinct values remain.