Convert array with duplicate values to object with number of repeated occurrences in JavaScript

Suppose, we have an array string that contains some duplicate entries like this −

const arr = ['California','Texas','Texas','Texas','New
York','Missouri','New Mexico','California'];

We are required to write a JavaScript function that takes in one such array. Our function should then construct an array of objects that contains an object for each unique entry and a property "count" that contains its count in the original array.

Therefore, the final output for the above array should look something like this −

const output = [
   {'name':'California', 'count':2},
   {'name':'Texas', 'count':3},
   {'name':'New York', 'count':1},
   {'name':'Missouri', 'count':1},
   {'name':'New Mexico', 'count':1},
];

Example

The code for this will be −

const arr = ['California','Texas','Texas','Texas','New York','Missouri','New Mexico','California'];
const findOccurrences = (arr = []) => {
   const res = [];
   arr.forEach(el => {
      const index = res.findIndex(obj => {
         return obj['name'] === el;
      });
      if(index === -1){
         res.push({
            "name": el,
            "count": 1
         })
      }
      else{
         res[index]["count"]++;
      };
   });
   return res;
};
console.log(findOccurrences(arr));

Output

And the output in the console will be −

[
   { name: 'California', count: 2 },
   { name: 'Texas', count: 3 },
   { name: 'New York', count: 1 },
   { name: 'Missouri', count: 1 },
   { name: 'New Mexico', count: 1 }
]