If you are using ES6/ES2015 or later you can do it this way: const data = [ { group: ‘A’, name: ‘SD’ }, { group: ‘B’, name: ‘FI’ }, { group: ‘A’, name: ‘MM’ }, { group: ‘B’, name: ‘CO’} ]; const unique = […new Set(data.map(item => item.group))]; // [ ‘A’, ‘B’] Here is an … Read more
Here you have some alternatives: http://www.peterbe.com/plog/uniqifiers-benchmark Fastest one: def f7(seq): seen = set() seen_add = seen.add return [x for x in seq if not (x in seen or seen_add(x))] Why assign seen.add to seen_add instead of just calling seen.add? Python is a dynamic language, and resolving seen.add each iteration is more costly than resolving a … Read more
TL;DR Using the Set constructor and the spread syntax: uniq = […new Set(array)]; “Smart” but naïve way uniqueArray = a.filter(function(item, pos) { return a.indexOf(item) == pos; }) Basically, we iterate over the array and, for each element, check if the first position of this element in the array is equal to the current position. Obviously, … Read more
With JavaScript 1.6 / ECMAScript 5 you can use the native filter method of an Array in the following way to get an array with unique values: function onlyUnique(value, index, self) { return self.indexOf(value) === index; } // usage example: var a = [‘a’, 1, ‘a’, 2, ‘1’]; var unique = a.filter(onlyUnique); console.log(unique); // [‘a’, … Read more