added code for iterator methods.

Author: atapas

index.js

@@ -422,3 +422,217 @@
     2: Promise.resolve('Apple'),
   }).then((array) => console.log(array));
 }
+
+// The Customer Array
+let customers = [
+  {
+     'id': 001,
+     'f_name': 'Abby',
+     'l_name': 'Thomas',
+     'gender': 'M',
+     'married': true,
+     'age': 32,
+     'expense': 500,
+     'purchased': ['Shampoo', 'Toys', 'Book']
+  },
+  {
+     'id': 002,
+     'f_name': 'Jerry',
+     'l_name': 'Tom',
+     'gender': 'M',
+     'married': true,
+     'age': 64,
+     'expense': 100,
+     'purchased': ['Stick', 'Blade']
+  },
+  {
+     'id': 003,
+     'f_name': 'Dianna',
+     'l_name': 'Cherry',
+     'gender': 'F',
+     'married': true,
+     'age': 22,
+     'expense': 1500,
+     'purchased': ['Lipstik', 'Nail Polish', 'Bag', 'Book']
+  },
+  {
+     'id': 004,
+     'f_name': 'Dev',
+     'l_name': 'Currian',
+     'gender': 'M',
+     'married': true,
+     'age': 82,
+     'expense': 90,
+     'purchased': ['Book']
+  },
+  {
+     'id': 005,
+     'f_name': 'Maria',
+     'l_name': 'Gomes',
+     'gender': 'F',
+     'married': false,
+     'age': 7,
+     'expense': 300,
+     'purchased': ['Toys']
+  }
+];
+
+// filter() method
+{
+  // filter example - Build Customer Data for Senior Citizens
+  const seniorCustomers = customers.filter((customer) => {
+    return (customer.age >= 60)
+  });
+  console.log('[filter] Senior Customers = ', seniorCustomers);
+}
+
+// map() method
+{
+  // map example - Build Customer Data with title and full name
+  const customersWithFullName = customers.map((customer) => {
+    let title = '';
+    if(customer.gender === 'M') {
+      title = 'Mr.';
+    } else if(customer.gender === 'F' && customer.married) {
+      title = 'Mrs.';
+    } else {
+      title = 'Miss';
+    }
+    customer['full_name'] = title 
+                            + " " 
+                            + customer.f_name 
+                            + " " 
+                            + customer.l_name;
+    return customer;
+  });
+  console.log('[map] Customers With Full Name = '
+                , customersWithFullName);
+}
+
+// reduce() method
+{
+  // reduce example - Get the Average Age of 
+  // Customers who purchased 'Book'
+  let count = 0;
+  const total = customers.reduce(
+    (accumulator, customer, currentIndex, array) => {
+        if(customer.purchased.includes('Book')) {
+          accumulator = accumulator + customer.age;
+          count = count + 1;
+        }
+        return (accumulator);
+    }, 
+  0);
+  console.log('[reduce] Customer Avg age Purchased Book:'
+                , Math.floor(total/count));
+}
+
+// some() method
+{
+  const hasYoungCustomer = customers.some((customer) => {
+    return (customer.age < 10);
+  });
+  console.log('[some] Has Young Customer(Age < 10):', hasYoungCustomer);
+}
+
+// find() method
+{
+  const foundYoungCustomer = customers.find((customer) => {
+      return (customer.age < 10);
+  });
+  console.log('[find] Found Young Customer(Age < 10): ', foundYoungCustomer);
+}
+
+// findIndex() method
+{
+  const index = customers.findIndex((customer) => {
+      return (customer.age < 10);
+  });
+}
+
+// findLastIndex() method
+{
+  const index = customers.findLastIndex((customer) => {
+      return (customer.age < 10);
+  });
+}
+
+// findLast() method
+{
+  const lastFoundYoungCustomer = customers.findLast((customer) => {
+      return (customer.age < 10);
+  });
+  console.log('[find] Last Found Young Customer(Age < 10): ', lastFoundYoungCustomer);
+}
+
+// every() method
+{
+  const isThereWindowShopper = customers.every((customer) => {
+      return (customer.purchased.length === 0);
+  })
+  console.log('[every] Is there a window shopper?', isThereWindowShopper);
+}
+
+// entries() method
+{
+  for (const value of numbers.entries()) {
+    console.log(value)
+  }
+}
+
+// values() method
+{
+  for (const value of numbers.values()) {
+    console.log(value)
+  }
+}
+
+// flatMap() method
+{
+  const arr1 = [1, 2, 3, 4];
+  arr1.map(item => item *2);
+  arr1.flatMap(item => item *2);
+
+  arr1.map(item => [item *2]);
+  arr1.flatMap(item => [item *2]);
+
+  arr1.map(item => [[item *2]]);
+  arr1.flatMap(item => [[item *2]])
+}
+
+// reduceRight() method
+{
+  let number = [100, 40, 15];
+
+  number.reduceRight((accumulator, current) => {
+      return accumulator - current
+  });
+}
+
+// Array method Chaining
+{
+  const marriedCustomers = customers.filter((customer) => {
+    return (customer.married);
+  });
+
+  const expenseMapped = marriedCustomers.map((marriedCustomer) => {
+    return marriedCustomer.expense;
+  });
+
+  const totalExpenseMarriedCustomer = expenseMapped.reduce(
+    (accum, expense) => {
+    return accum + expense;
+   }, 0);
+   console.log('Total Expense of Married Customers in INR: '
+   , totalExpenseMarriedCustomer);
+
+  // After Chining them
+  const total = customers
+                   .filter(customer => customer.married)
+                   .map(married => married.expense)
+                   .reduce((accum,expense) => accum + expense);
+  console.log('Orchestrated total expense in INR: ', total);
+}
+
+
+

readme.md

@@ -61,21 +61,21 @@ COMING SOON. This course is being planned to be part of the upcoming super serie
         -   [X] The Array.from() array method
         -   [X] The Array.fromAsync() array method
         -   [X] The Array.of() array method
-    -   [ ] Array Iterator Methods in JavaScript
-        -   [ ] The filter() array method
-        -   [ ] The map() array method
-        -   [ ] The flatMap() array method
-        -   [ ] The reduce() array method
-        -   [ ] The reduceRight() array method
-        -   [ ] The some() array method
-        -   [ ] The find() array method
-        -   [ ] The findIndex() array method
-        -   [ ] The findLast() array method
-        -   [ ] The findLastIndex() array method
-        -   [ ] The forEach() array method
-        -   [ ] The every() array method
-        -   [ ] The entries() method
-        -   [ ] The value() method
+    -   [X] Array Iterator Methods in JavaScript
+        -   [X] The filter() array method
+        -   [X] The map() array method
+        -   [X] The flatMap() array method
+        -   [X] The reduce() array method
+        -   [X] The reduceRight() array method
+        -   [X] The some() array method
+        -   [X] The find() array method
+        -   [X] The findIndex() array method
+        -   [X] The findLast() array method
+        -   [X] The findLastIndex() array method
+        -   [X] The forEach() array method
+        -   [X] The every() array method
+        -   [X] The entries() method
+        -   [X] The values() method
     -   [X] Immutability
         -   [X] The toReversed() method
         -   [X] The toSorted() method