Duplicate an array (make a copy, not reference)

duplcArray.js

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

// Spread Operator  
const arr1 = [...arr];

// Slice Operator
const arr2 = arr.slice();

// Concat
const arr3 = [].concat(arr)

// Array.from()
const arr4 = Array.from(arr);

// For loop
function arr5(arr) {
  let newArr = [];
  for(let i=0; i<arr.length; ++i) {
      newArr[i] = arr[i];
  }
  return arr;
}

// Deep copy
const dupArray = JSON.parse(JSON.stringify(arr))

This code from William Vincent blog, JavaScript: Duplicate an Array