Algorithm-Diff-Two-Arrays.md

Algorithm Diff Two Arrays

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🏁 Problem Explanation:

Check two arrays and return a new array that contains only the items that are not in either of the original arrays.

Relevant Links

• for Loop (Devdocs)
• Array.prototype.includes (Devdocs)
• Array.prototype.filter (Devdocs)
• Array.prototype.concat (Devdocs)

💬 Hint: 1

Merge the list to make it easy to compare functions.

try to solve the problem now

💬 Hint: 2

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

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💬 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.

try to solve the problem now

Spoiler Alert!

Solution ahead!

🔰 Basic Code Solution (Imperative Solution):

function diffArray(arr1, arr2) {
  var newArr = [];
  // Looping through arr1 to find elements that do not exist in arr2  
  for (var i = 0; i < arr1.length; i++) {
    if (arr2.indexOf(arr1[i]) === -1){
      // Pushing the unique to arr1 elements to the newArr
      newArr.push(arr1[i]);
    }
  }
  // Looping through arr2 to find elements that do not exist in arr1
  for (var j = 0; j < arr2.length; j++) {
    if (arr1.indexOf(arr2[j]) === -1){
      // Pushing the unique to arr2 elements to the newArr    
      newArr.push(arr2[j]);
    }
  }

  return newArr;
}

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

Run Code 🚀

Code Explanation:

Read the comments in the code.

Relevant Links

• for Loop (Devdocs)

🌻 Intermediate Code Solution (Declarative Solution):

function diffArray(arr1, arr2) {
  return arr1
    .concat(arr2)
    .filter(
        item => !arr1.includes(item) || !arr2.includes(item)
    )
}

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

Run Code 🚀

Code Explanation:

Explain solution here and add any relevant links

Relevant Links

• Array.prototype.concat (Devdocs)
• Array.prototype.filter (Devdocs)
• Array.prototype.includes (Devdocs)

🚨 Advanced Code Solution (Declarative Solution):

function diffArray(arr1, arr2) {
    return arr1
      .filter(el => !arr2.includes(el))
      .concat(
        arr2.filter(el => !arr1.includes(el))
      )
}

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

Run Code 🚀

Code Explanation:

Explain solution here and add any relevant links

Relevant Links

• Array.prototype.includes (Devdocs)
• Array.prototype.filter (Devdocs)
• Array.prototype.concat (Devdocs)

🏆 Credits:

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Thanks @Rafase282 @aganita @abhisekp for your help with Challenge: Diff Two Arrays

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