var numbers= [2, 4, 5, 37, 0]
var duplicate_numbers = {}

enter code here for (var i = 0; i < numbers.length; ++i) {
duplicate_numbers.push( numbers[i]*2 );
    duplicate_numbers.push( i );}

const numbers_duplicates = {};
const numbers =  [2, 4, 5, 37, 0];

numbers.forEach(number => { numbers_duplicates[number] = number * 2 });

const numbers = [2, 4, 5, 37, 0] ;
const duplicateNumbers = {};
const numbersSorted = numbers.sort((a, b) => a - b);

for (let i = 0; i < numbersSorted.length; i++) {
  duplicateNumbers[numbersSorted[i]] = numbersSorted[i] * 2;
}