// 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']