1loc.dev/
const countOccurrences = arr => arr.reduce((prev, curr) => (prev[curr] = ++prev[curr] || 1, prev), {});
// Examples countOccurrences([2, 1, 3, 3, 2, 3]); // { '1': 1, '2': 2, '3': 3 } countOccurrences(['a', 'b', 'a', 'c', 'a', 'b']); // { 'a': 3, 'b': 2, 'c': 1 }
This is good!
Do look at the other functions in 1loc.dev
I liked this trick:
++prev[curr] || 1
Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink.
Hide child comments as well
Confirm
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
1loc.dev/
const countOccurrences = arr => arr.reduce((prev, curr) => (prev[curr] = ++prev[curr] || 1, prev), {});
// Examples
countOccurrences([2, 1, 3, 3, 2, 3]); // { '1': 1, '2': 2, '3': 3 }
countOccurrences(['a', 'b', 'a', 'c', 'a', 'b']); // { 'a': 3, 'b': 2, 'c': 1 }
This is good!
Do look at the other functions in 1loc.dev
I liked this trick: