Extract strings with unique characters from javascript Array

Question

I want to extract only those strings which have unique characters, I have an array of strings:

var arr = ["abb", "abc", "abcdb", "aea", "bbb", "ego"];
Output: ["abc", "ego"]

I tried to achieve it using Array.forEach() method:

 var arr = ["abb", "abc", "abcdb", "aea", "bbb", "ego"]; const filterUnique = (arr) => { var result = []; arr.forEach(element => { for (let i = 0; i <= element.length; i++) { var a = element[i]; if (element.indexOf(a, i + 1) > -1) { return false; } } result.push(element); }); return result; } console.log(filterUnique(arr));

Want to know is any other way to achieve this task ?

Any suggestion.

Answer 1

I'd .filter by whether the size of a Set of the string is the same as the length of the string:

 const filterUnique = arr => arr .filter(str => new Set(str).size === str.length); console.log(filterUnique(["abb", "abc", "abcdb", "aea", "bbb", "ego"]));

(a Set will not hold duplicate elements, so, eg, if 4 elements are put into a set and 2 are duplicates of others, the resulting size of the Set will be 2)

Answer 2

You can check by creating sets from strings also, a Set object will always have unique values.

 var a = ["abb", "abc", "abcdb", "aea", "bbb", "ego"]; console.log(a.filter(v => v.length === new Set(v).size))