 # Object with the number of elements in the array in JavaScript

Let's have an array:

`let arr = ['a', 'b', 'c', 'a', 'a', 'b'];`

Let's count how many and what elements there are in this array and present the result as an object like this:

`{a: 3, b: 2, c: 1}`

To solve this, let's make the object `count` with the following initial values:

`let count = {a: 0, b: 0, c: 0}`

We will loop through the array and increase the corresponding value in the object `count`:

```let arr = ['a', 'b', 'c', 'a', 'a', 'b']; let count = {a: 0, b: 0, c: 0}; for (let elem of arr) { count[elem]++; } console.log(count); // shows {a: 3, b: 2, c: 1}```

Let's go further: the fact that the object `count` has characters listed in the initial values, because we usually do not know what elements are in the array.

Let the object `count` be formed automatically in this way: if there is no such element in `count`, then it should be assigned the value `1`, and if there is, just increase the value by one:

```let arr = ['a', 'b', 'c', 'a', 'a', 'b']; let count = {}; for (let elem of arr) { if (count[elem] === undefined) { count[elem] = 1; } else { count[elem]++; } } console.log(count); // shows {a: 3, b: 2, c: 1}```

Given a string. Count how many times each of its characters occurs in it.