Diff Two Arrays - how can i get this done simultaneously to avoid repetition?

JavaScript
1

I thought I was on the code with this but I realised that the code will output the different elements in a new array TWICE…

Is there no function to check all elements of an array for multiple arrays and compare elements? I tried .includes , if that’s the right one can someone give me a pointer on how to fix this?

Your code so far


function diffArray(arr1, arr2) {
  var newArr = [];
  

for (let i = 0 ; i<arr1.length ; i++) {


if ( (arr1.includes(arr2[i])) === false ) {

  newArr.push(arr2[i]);

  console.log(newArr);

} else if ( (arr2.includes(arr1[i])) === false ) {

  newArr.push(arr1[i]);

}


}



  return newArr;
}



console.log(diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]));

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/diff-two-arrays/

3

so an if statement to check if the lengths are not equal.

if (arr1.length !=arr2.length)

hmm… what I’m thinking atm is that if either is unequal, to extend the length by the difference of what their length is

But that would lead to empty/ null elements then we have the same problem in the end ultimately when all are compared, newArr will have null elements if both arrays do not share that :S

6

This explanation is excellent, thank you.
This is my new attempt via converting your logic into code - it’s better than the other one but I’m still slipping somewhere. Today has been a long day so I’m sure I’ll get it tomorrow. Give pointers when you can thank you

function diffArray(arr1, arr2) {

var newArr = [];

if (arr1.length &gt; arr2.length)

{

for (let i = 0 ; i&lt;arr1.length ; i++) {

if ( (arr2.includes(arr1[i]) == false) &amp;&amp; ((arr2[i] !== undefined))) {

newArr.push(arr1[i]);

}

} } else {

for (let i = 0; i&lt;arr2.length; i++) {

if ( (arr1.includes(arr2[i]) == false) &amp;&amp; ((arr1[i] !== undefined)) ) {

if (arr1[i] != undefined) {

newArr.push(arr2[i]);

}

}

}

}

return newArr;

}