Return a Sorted Array Without Changing the Original Array

JavaScript
1

Tell us what’s happening:
I know I’m missing something obvious to complete this challenge, but with the code below, I keep getting the following error message:

“nonMutatingSort(globalArray) should return [2, 3, 5, 6, 9].”

Please can someone put me out of my misery and help me with the correct code? :slight_smile:

Your code so far


var globalArray = [5, 6, 3, 2, 9];
function nonMutatingSort(arr) {
  // Add your code below this line
  var newArray = arr.concat(globalArray); 
  newArray.sort(function(a, b) {return a-b});
  return newArray;
  // Add your code above this line
}
nonMutatingSort(globalArray);

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/functional-programming/return-a-sorted-array-without-changing-the-original-array/

2

You are copying your array twice.
If you print newArray to the console, you will see the following array: [5, 6, 3, 2, 9, 5, 6, 3, 2, 9];
This causes your answer to be wrong. All you need to do is remove “globalArray” from your concat function.

1 Like
3

Of course - thank you!

4

This is my solution:

var globalArray = [5, 6, 3, 2, 9];
function nonMutatingSort(arr) {
  return [].concat(arr).sort( (a,b) => a > b );
}
nonMutatingSort(globalArray);
8 Likes
5

I came up with this easy solution

var globalArray = [5, 6, 3, 2, 9];
function nonMutatingSort(arr) {
// Add your code below this line
var newArray = arr.concat();
return newArray.sort();

// Add your code above this line
}
nonMutatingSort(globalArray);

1 Like
6

Guys you don’t read the instructions

<code >return globalArray.concat([]).sort() </code>

1 Like
7

I would rather use arr instead of GlobalArray - this is more functional programming way - lets you use this function with other arrays.

1 Like
8

var globalArray = [5, 6, 3, 2, 9];
var temp = [];
function nonMutatingSort(arr) {
// Add your code below this line
var temp1 = temp.concat(globalArray);
temp1.sort(function(a,b){
return a-b;
});
// Add your code above this line
return temp1;
}
nonMutatingSort(globalArray);

9

Here is my code :slight_smile:

var globalArray = [5, 6, 3, 2, 9];
function nonMutatingSort(arr) {
  // Add your code below this line
  let array = [].concat(arr)
  array.sort()

  return [].concat(array)

  
  // Add your code above this line
}
nonMutatingSort(globalArray);