feat(curriculum): add lab for building a symmetric difference function (freeCodeCamp#61950)

Co-authored-by: Ilenia <26656284+ilenia-magoni@users.noreply.github.com>

Author: Sembauke

client/i18n/locales/english/intro.json

@@ -3486,6 +3486,12 @@
           "In this lab, you will create a function that finds the index at which a given number should be inserted into a sorted array to maintain the array's sorted order."
         ]
       },
+      "lab-symmetric-difference": {
+        "title": "Build a Symmetric Difference Function",
+        "intro": [
+          "In this lab, you will practice using higher order functions to find the symmetric difference between two arrays."
+        ]
+      },
       "review-javascript-higher-order-functions": {
         "title": "JavaScript Higher Order Functions Review",
         "intro": [

client/src/pages/learn/full-stack-developer/lab-symmetric-difference/index.md

@@ -0,0 +1,9 @@
+---
+title: Build a Symmetric Difference Function
+block: lab-symmetric-difference
+superBlock: full-stack-developer
+---
+
+## Introduction to the Symmetric Difference Function
+
+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.

curriculum/challenges/english/blocks/lab-symmetric-difference/68ad9821ee41baad9cb0fd4e.md

@@ -0,0 +1,88 @@
+---
+id: 68ad9821ee41baad9cb0fd4e
+title: Build a Symmetric Difference Function
+challengeType: 25
+dashedName: lab-symmetric-difference
+---
+
+# --description--
+
+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.
+
+Example:
+
+- Array A: `["diamond", "stick", "apple"]`
+
+- Array B: `["stick", "emerald", "bread"]`
+
+Result: `["diamond", "apple", "emerald", "bread"]`
+
+**Objective:** Fulfill the user stories below and get all the tests to pass to complete the lab.
+
+**User Stories:**
+
+1. Your function `diffArray` should return an array.
+2. Your function should take two arguments, both of which are arrays.
+3. Your function should make use of the `filter` method.
+4. Your function should return the symmetric difference of the two arrays.  
+5. Your function should return an empty array if there is no symmetric difference.
+
+
+# --hints--
+
+You should have a function named `diffArray`.
+
+```js
+assert.isFunction(diffArray);
+```
+
+The `diffArray` function should use the `filter` method to filter out items that are present in both arrays.
+
+```js
+assert(/\.filter\(/.test(diffArray.toString()));
+```
+
+`diffArray(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"])` should return `["pink wool"]`.
+
+```js
+assert.deepEqual(diffArray(
+  ["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"],
+  ["diorite", "andesite", "grass", "dirt", "dead shrub"]
+), ["pink wool"]);
+```
+
+`diffArray*["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["andesite", "grass", "dirt", "dead shrub"])` should return `["diorite", "pink wool"]`.
+
+```js
+assert.deepEqual(diffArray(
+  ["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"],
+  ["andesite", "grass", "dirt", "dead shrub"]
+), ["diorite", "pink wool"]);
+```
+
+`diffArray` should return an empty array when called with two identical arrays.
+
+```js
+assert.deepEqual(diffArray(
+  ["andesite", "grass", "dirt", "dead shrub"],
+  ["andesite", "grass", "dirt", "dead shrub"]
+), []);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```js
+
+```
+
+# --solutions--
+
+```js
+function diffArray(arr1, arr2) {
+  return arr1
+    .filter(item => !arr2.includes(item))
+    .concat(arr2.filter(item => !arr1.includes(item)));
+}
+```

curriculum/structure/blocks/lab-symmetric-difference.json

@@ -0,0 +1,14 @@
+{
+  "name": "Build a Symmetric Difference Function",
+  "isUpcomingChange": false,
+  "dashedName": "lab-symmetric-difference",
+  "helpCategory": "JavaScript",
+  "challengeOrder": [
+    {
+      "id": "68ad9821ee41baad9cb0fd4e",
+      "title": "Build a Symmetric Difference Function"
+    }
+  ],
+  "blockLayout": "link",
+  "blockType": "lab"
+}

curriculum/structure/superblocks/full-stack-developer.json

@@ -395,6 +395,7 @@
             "workshop-library-manager",
             "lab-book-organizer",
             "lab-sorted-index-finder",
+            "lab-symmetric-difference",
             "review-javascript-higher-order-functions",
             "quiz-javascript-higher-order-functions"
           ]