nonMutatingPush.js

// *** Functional Programming: Add Elements to the End of an Array Using concat Instead of push ***

// Functional programming is all about creating and using non-mutating functions.

// The last challenge introduced the concat method as a way to combine arrays into a new 
// one without mutating the original arrays. Compare concat to the push method. Push adds 
// an item to the end of the same array it is called on, which mutates that array. 

// Here's an example:
//   var arr = [1, 2, 3];
//   arr.push([4, 5, 6]);
//   arr is changed to [1, 2, 3, [4, 5, 6]]
//   Not the functional programming way

// Concat offers a way to add new items to the end of an array without any mutating side effects.

// Change the nonMutatingPush function so it uses concat to add newItem to the end of original
// instead of push. The function should return an array.


function nonMutatingPush(original, newItem) {
  // Add your code below this line
  return original.concat(newItem);
  
  // Add your code above this line
}
var first = [1, 2, 3];
var second = [4, 5];
nonMutatingPush(first, second);