diff_two_arrays.js

/*

Compare two arrays and return a new array with any items only found in one of the two given arrays, 

but not both. In other words, return the symmetric difference of the two arrays.

*/

function diffArray(arr1, arr2) {
    let newArr = arr1.concat(arr2);

    let newerArr = newArr.filter((i) => {
        return !arr1.includes(i) || !arr2.includes(i);
    });
    console.log(newerArr);

    return newerArr;
}

diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]); //should return [4].

diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]); // should return ["pink wool"].
diffArray(["andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]) // should return ["diorite", "pink wool"].
diffArray(["andesite", "grass", "dirt", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"]) //should return [].

diffArray([1, "calf", 3, "piglet"], [1, "calf", 3, 4]) //should return ["piglet", 4].
diffArray([], ["snuffleupagus", "cookie monster", "elmo"]) //should return ["snuffleupagus", "cookie monster", "elmo"].
diffArray([1, "calf", 3, "piglet"], [7, "filly"]) //should return [1, "calf", 3, "piglet", 7, "filly"].