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Gilbert Joseph Smith III

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Details

• Difficulty: 2/5

Compare two arrays and return a new array with any items not found in both of the original arrays.

Remember to use Read-Search-Ask if you get stuck. Try to pair program. Write your own code.

Useful Links

• Comparison Operators
• Array.slice()
• Array.filter()
• Array.indexOf()
• Array.concat()

Problem Script:

function diff(arr1, arr2) {
  var newArr = [];
  // Same, same; but different.
  return newArr;
}

diff([1, 2, 3, 5], [1, 2, 3, 4, 5]);

Problem Explanation:

• You will check two arrays and return a new array that contains only the items that are not in either of the original arrays.

Hint: 1

• Merge the list to make it easy to compare functions.

Hint: 2

• Use filter to get the new array, you will need to create a callback function.

Hint: 3

• The best way to go about the callback function is to check if the number from the new merged array is not in both original arrays and return it.

Spoiler Alert!

Solution ahead!

Code Solution:

function diff(arr1, arr2) {
  var newArr = arr1.concat(arr2);

  function check(item) {
    if (arr1.indexOf(item) === -1 || arr2.indexOf(item) === -1) {
      return item;
    }
  }

  return newArr.filter(check);
}

Code Explanation:

• Merge both arrays on the new one using .concat()
• Create a callback function to use with filter. The function will check if the number is not present in both original arrays and return it.
• Return the filtered array.