feat: add tutorial of arrays methods

Author: MikhailMasny

index.html

@@ -21,5 +21,6 @@
     <!-- <script src="src/proxy.js"></script> -->
     <!-- <script src="src/generator.js"></script> -->
     <!-- <script src="src/symbol.js"></script> -->
+    <!-- <script src="src/arrays-methods.js"></script> -->
 </body>
 </html>

src/arrays-methods.js

@@ -0,0 +1,91 @@
+const array = [
+    { prop1: "One", prop2: 1 },
+    { prop1: "Two", prop2: 2 },
+    { prop1: "Three", prop2: 3 },
+    { prop1: "Four", prop2: 4 },
+    { prop1: "Five", prop2: 5 }
+]
+
+// for (ES5)
+console.group("for");
+
+for (let index = 0; index < array.length; index++) {
+    const element = array[index];
+    console.log(element);
+}
+
+console.groupEnd();
+
+// for..of (ES6)
+console.group("for..of");
+
+for (const element of array) {
+    console.log(element);
+}
+
+console.groupEnd();
+
+// forEach
+console.group("forEach");
+
+array.forEach(function(element, index, pArr) {
+    console.log(element);
+    console.log(index);
+    console.log(pArr);
+    console.log("-----")
+})
+
+array.forEach(element => {
+    console.log(element);
+});
+
+console.groupEnd();
+
+// Map
+console.group("Map");
+
+const newArray = array.map(element => {
+    return element;
+});
+console.log(newArray);
+
+const someArray = array.map(element => {
+    return `Prop1: ${element.prop1}, prop2: ${element.prop2}`;
+});
+console.log(someArray);
+
+console.groupEnd();
+
+// Filter
+console.group("Filter");
+
+const filteredArray = array.filter(element => element.prop2 >= 3);
+console.log(filteredArray);
+
+console.groupEnd();
+
+// Reduce
+console.group("Reduce");
+
+const sumArray = array.reduce((total, element) => {
+    return total + element.prop2;
+}, 0);
+console.log(sumArray);
+
+console.groupEnd();
+
+// Find
+console.group("Find");
+
+const itemTwo = array.find(element => element.prop1 === "Two");
+console.log(itemTwo);
+
+console.groupEnd();
+
+// FindIndex
+console.group("FindIndex");
+
+const itemFourIndex = array.findIndex(element => element.prop1 == "Four");
+console.log(itemFourIndex);
+
+console.groupEnd();