const myArray = [1, 3, 5, 7];

function callback(elem, index, array) {
  return {e: elem + 10, i: index - 1, arr: array};
}

function myMap(arr){
  const newArray = [];
  for (let i = 0; i < arr.length; i++){
    newArray.push(callback(arr[i], i, arr));
  }
  return newArray;
}

const result = myMap(myArray);
console.log(result);