find unique values in array and count javascript

Question

so i have an array like this, that i want to find the unique value with then count:

users: 
   [ '21000316',
     '21000316',
     '21000316',
     '21000316',
     '22000510',
     '22000510',
     '22000510',
     '22000510' ]

is it possible for me to get the unique value and count it from the array without using sort()? and turn it into this value i try some code but only get the count and the unique value separetely:

{'21000316':4,'21000510':4}

Check this, stackoverflow.com/a/49156466/7785337 . Just replace the array values with your's, you ll get the result. — Maniraj Murugan
– Maniraj Murugan, Commented Nov 15, 2022 at 4:50

Finbar · Accepted Answer · 2022-11-15 04:51:18Z

2

Probably a better approach but you can create an object and then sort through all array elements adding +1 to the object.

const users = ['1', '1', '2', '3', '3', '3', '3'];
const result = {};

for(const user in users)
  result[users[user]] = (result[users[user]] || 0) + 1;

console.log(result);

edited Nov 15, 2022 at 4:51

answered Nov 15, 2022 at 4:44

Finbar

1,3741 gold badge8 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

JS24 Over a year ago

it return this :{ '2022-11-12': 1, '2022-11-14': 1 }

Finbar Over a year ago

Refresh your answer

score 2 · Accepted Answer · 2022-11-15 19:06:41Z

2

const users = [
     '21000316',
     '21000316',
     '21000316',
     '21000316',
     '22000510',
     '22000510',
     '22000510',
     '22000510'
];
console.log(users.reduce((m, k) => { m[k] = m[k] + 1 || 1; return m }, {}));

edited Nov 15, 2022 at 19:06

answered Nov 15, 2022 at 4:54

user9706

Comments

dangerousmanleesanghyeon · Accepted Answer · 2022-11-15 04:59:35Z

1

let users =  [ '21000316',
     '21000316',
     '21000316',
     '21000316',
     '22000510',
     '22000510',
     '22000510',
     '22000510' ];
     
let set = new Set(users);

let res = [...set.keys()].reduce((pre, cur) => {
    pre[cur] = users.filter(u => u === cur).length;
    return pre;
}, {})

console.log(res)

answered Nov 15, 2022 at 4:59

dangerousmanleesanghyeon

5734 silver badges12 bronze badges

Collectives™ on Stack Overflow

find unique values in array and count javascript

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related