Count array duplicates and display the result.

by Jithin Raj P R

JavaScript

const arr = [1, 1, 2, 3, 3, 4, 5];


function countArray(arr){
  const duplicate = [];
  const count = {};

  for(let item of arr){
    count[item] = (count[item] || 0) + 1;
  }

  for(let key in count) {
    if (count[key] > 1) {
    duplicates.push(Number(key));
  }
  }

  console.log(count)
}

console.log(countArray(arr))

//output: 1-2, 2-1, 3-2, 4-1, 5-1