02 Basics / 04 Objects JS

Learned about constructors method, objects into objects, combining objects, array of objects and some important syntax to access objects.

Author: aayushyadavz

02_Basics/04_objects.js

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+// 4. Objects,
+
+const tinderUser = new Object() // Singleton Object
+// console.log(tinderUser); // Output: {}
+
+const tinderUserTwo = {} // Non-singleton Object
+// console.log(tinderUserTwo); // Output: {}
+
+tinderUserTwo.id = "123abc"
+tinderUserTwo.name = "sammy"
+tinderUserTwo.isLoggedIn = false
+// console.log(tinderUserTwo); // Output: { id: '123abc', name: 'sammy', isLoggedIn: false }
+
+/*-------------------------------------------------------------------------------------------------
+Objects into Objects, */
+const regularUser = {
+    email: "someuser@gmail.com",
+    fullName: {
+        usersName: {
+            firstName: "Ayush",
+            lastName: "Yadav"
+        }
+    }
+}
+// console.log(regularUser.fullName.usersName.lastName); // Output: Yadav
+
+//-------------------------------------------------------------------------------------------------
+const obj1 = {1: "a", 2: "b"}
+const obj2 = {3: "a", 4: "b"}
+// Combining Objects,
+// const obj3 = Object.assign({}, obj1, obj2) // {} Target | obj1, obj2 Source
+// console.log(obj3); // Output: { '1': 'a', '2': 'b', '3': 'a', '4': 'b' }
+// const obj3 = {...obj1, ...obj2} // used most of the time
+// console.log(obj3); // Output: { '1': 'a', '2': 'b', '3': 'a', '4': 'b' }
+
+/*-------------------------------------------------------------------------------------------------
+Array of Objects, */
+const user = [
+    {
+        id: 1,
+        email: "h@gmail.com"
+    },
+    {
+        id: 2,
+        email: "i@gmail.com"
+    },
+    {
+        id: 3,
+        email: "j@gmail.com"
+    },
+    {
+        id: 4,
+        email: "k@gmail.com"
+    }
+]
+// console.log(user[2].email); // Output: j@gmail.com
+
+/*-------------------------------------------------------------------------------------------------
+Some more impotant syntax, */
+console.log(Object.keys(tinderUserTwo)); // Output: [ 'id', 'name', 'isLoggedIn' ]
+console.log(Object.values(tinderUserTwo)); // Output: [ '123abc', 'sammy', false ]
+console.log(Object.entries(tinderUserTwo)); /* Output: [ [ 'id', '123abc' ], [ 'name', 'sammy' ], 
+[ 'isLoggedIn', false ] ] 
+
+Checking Property exist or not, */
+console.log(tinderUserTwo.hasOwnProperty('isLoggedIn')); // Output: true