Add examples for find() and findIndex() array methods.

Tutorials/38_find_findIndex.js

@@ -0,0 +1,52 @@
+const users = [
+  { name: 'Alex', last_name: 'Ventura', age: 19},
+  { name: 'Joe', last_name: 'Blink', age: 11},
+  { name: 'Nick', last_name: 'Doe', age: 26},
+  { name: 'Nina', last_name: 'Michael', age: 6}
+]
+
+/* find() method:
+ * it returns the first element from the provided array that matches the provided criteria function.
+ * If any values meets the criteria, `undefined` is returned.
+ */
+
+// We want to find a user with name 'Nick' within the users collection.
+// So we use the find() method and pass a function as an argument.
+const nick = users.find(function(element) {
+  // Element represents each user in the users collection and will respond to any of its properties like `name`.
+  return element.name === 'Nick';
+});
+
+// Espected output si an Object:
+console.log(nick);
+
+// This is the short version using an arrow function
+const nickArrow = users.find(element => element.name === 'Nick');
+console.log(nickArrow);
+
+
+
+
+
+
+/* findIndex() method:
+ * it returns the index (position starting from 0) of the first element in the provided array that matches the provided criteria function.
+ * If any element meets the testing criteria, then -1 is returned.
+ */
+
+// In this case, we want to know the position of a user within the users collection, so that we can delete it.
+const indexPositionOfJoe = users.findIndex(function(element) {
+  return element.name === 'Joe';
+});
+
+// Expected output is an integer not an object:
+console.log(indexPositionOfJoe);
+
+//Now we can delete the users using splice function:
+users.splice(indexPositionOfJoe, 1);
+
+// Now we should not see Joe in the users collection:
+console.log(users);
+
+// This is the findIndex short-version using an arrow function
+const indexPositionOfJoeArrow = users.findIndex(element => element.name === 'Joe');