1_.uniq([2, 1, 2]);
2// => [2, 1]
3 
4// using `isSorted`
5_.uniq([1, 1, 2], true);
6// => [1, 2]
7 
8// using an iteratee function
9_.uniq([1, 2.5, 1.5, 2], function(n) {
10  return this.floor(n);
11}, Math);
12// => [1, 2.5]
13 
14// using the `_.property` callback shorthand
15_.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
16// => [{ 'x': 1 }, { 'x': 2 }]

1const _quote_filter = _.map(quote_state, (val, key) => {   if (val) {      return key   }})console.log(_quote_filter) //=> [ 'btc', undefined, undefined ]