// usage example:
var myArray = ['a', 1, 'a', 2, '1'];
var unique = myArray.filter((v, i, a) => a.indexOf(v) === i);
// unique is ['a', 1, 2, '1']const categories = ['General', 'Exotic', 'Extreme', 'Extreme', 'General' ,'Water', 'Extreme']
.filter((value, index, categoryArray) => categoryArray.indexOf(value) === index);
This will return an array that has the unique category names
['General', 'Exotic', 'Extreme', 'Water']
var myArray = ['a', 1, 'a', 2, '1'];
let unique = [...new Set(myArray)];
console.log(unique); // unique is ['a', 1, 2, '1']