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array-methods/1-array.js

@@ -6,34 +6,94 @@ var strings = ["this", "is", "a", "collection", "of", "words"];
 
 // Find largest number in numbers
 
+var maxNum = Math.max(...numbers);
+console.log(maxNum);
+
 // Find longest string in strings
 
+var lengthArray = [];
+var num = 0;
+var longestString = "";
+strings.forEach(function(element) {
+  if (element.length > num) {
+    num = element.length;
+    longestString = element;
+  }
+});
+
 // Find all the even numbers
 
+var evenArray = numbers.filter(element => element % 2 == 0);
+console.log(evenArray); // [12, 4, 18, 6]
+
 // Find all the odd numbers
 
+var oddArray = numbers.filter(element => element % 2);
+console.log(oddArray); // [1, 9, 7, 11, 3, 101, 5]
+
 // Find all the words that contain 'is' use string method 'includes'
 
+var containsIs = strings.filter(element => element.includes("is"));
+console.log(containsIs);
+
 // Find all the words that contain 'is' use string method 'indexOf'
 
+var arr = [];
+var containsIsss = strings.forEach(function(element) {
+	if (element.indexOf("is") != -1) {arr.push(element);}
+});
+arr; // ["this", is]
+
 // Check if all the numbers in numbers array are divisible by three use array method (every)
 
+var divisibleByThree = numbers.every(function(element) {element % 3 == 0});
+divisibleByThree // false
+
 //  Sort Array from smallest to largest
 
+var sortStr = strings.sort();
+var numArray = numbers.sort(function (a, b) {return a-b;});
+
+sortStr; // ["a", "collection", "is", "of", "swastik"]
+numArray; // [1, 3, 4, 5, 6, 7, 9, 11, 12, 18, 101]
+
 // Remove the last word in strings
 
+strings.pop();
+strings // ["this", "is", "a", "collection", "of"]
+
 // Add a new word in the array
 
+strings.push("newWord");
+strings // ["this", "is", "a", "collection", "of", "newWord"]
+
 // Remove the first word in the array
 
+strings.shift();
+strings // ["is", "a", "collection", "of", "newWord"]
+
 // Place a new word at the start of the array use (upshift)
 
+strings.unshift("Hello");
+strings // ["Hello", "is", "a", "collection", "of", "newWord"]
+
 // Make a subset of numbers array [18,9,7,11]
 
+var subSet = numbers.slice(3, 7);
+subSet; // [18, 9, 7, 11];
+
 // Make a subset of strings array ['a','collection']
 
+var subStr = strings.slice(3, 7);
+subStr; // ["a", "collection"]
+
 // Replace 12 & 18 with 1221 and 1881
 
+numbers.splice(3, 1, 1881);
+numbers.splice(1, 1, 1221);
+
+numbers; // [1, 1221, 4, 1881, 9, 7, 11, 3, 101, 5, 6]
+
 // Replace words with string in strings array
 
 // Customers Array
@@ -45,6 +105,17 @@ var customers = [
 ];
 // Find all customers whose firstname starts with 'J'
 
+var startWithJ = customers.filter(element => element.firstname.startsWith('J'));
+startWithJ;
+
 // Create new array with firstname and lastname
 
+var nameArray = [];
+var name = customers.forEach(function(element) {
+  nameArray.push(`${element.firstname} + ${element.lastname}`);
+});
+nameArray; // ["Joe Blogs", "John Smith", "Dave Jones", "Jack White"]
+
 // Sort the array created above alphabetically
+
+nameArray.sort(); // ["Dave Jones", "Jack White", "Joe Blogs", "John Smith"]

array-methods/2-array.js

@@ -10,6 +10,16 @@ var words = [
 //Write a function findLongestWord that takes an array of words and returns the longest one.
 //If there are 2 with the same length, it should return the first occurrence.
 
+var lengthArray = [];
+var num = 0;
+var longestString = "";
+words.forEach(function(element) {
+  if (element.length > num) {
+    num = element.length;
+    longestString = element;
+  }
+});
+// This will return the first occurence of longest word.
 
 
 
@@ -18,14 +28,24 @@ var numbers1 = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
 // Use reduce method of array
 // Use the above sum and calculate the average.
 
+var reducer = (accumulator, currentValue) => accumulator + currentValue;
+var sum1 = numbers1.reduce(reducer);
 
-
+var avg1 = sum / numbers1.length;
+avg1; // 8.7
 
 var numbers2 = [2, 6, 9, 10, 7, 4, 1, 9];
 //Write a function averageNumbers that receives an array of numbers2 and calculate the average of the numbers
 
 
-
+var sum2 = 0;
+function averageNumbers(numArray) {
+  numArray.forEach(function(element) {
+    sum2 += element;
+  });
+  return sum2 / numArray.length;
+}
+averageNumbers(numbers2); // 48 / 8 = 6.
 
 var words2 = [
   'seat',
@@ -41,5 +61,12 @@ var words2 = [
 ];
 //Write a function averageWordLength that receives an array of words2 and calculate the average length of the words.
 
-
-
+var word2len = 0;
+function avgWords(words2) {
+  words2.forEach(function(element) {
+    word2len += element.length;
+  });
+  var wordAvg = word2len / words2.length;
+  return wordAvg;
+}
+avgWords(words2); // 5.3

array-methods/3-array.js

@@ -15,6 +15,11 @@ var words = [
 // Write a function uniqueArray that receives an array of words as a parameter. And remove the duplicates, and return a new array. 
 // (indexOf)
 
+function uniqueArray(words) {
+  var wordsFilter = words.filter((element, index) => words.indexOf(element) == index);
+  return wordsFilter;
+} 
+
 
 
 var words2 = [
@@ -30,6 +35,11 @@ var words2 = [
 
 // Write a function doesWordExist that will take in an array of words as one argument, and a word to search for as the other. Return true if it exists, otherwise, return false. Don't use indexOf for this one.
 
+function doesWordExist(words2, searchItem) {
+  return words2.includes(searchItem);
+}
+
+doesWordExist(words2, 'machine'); // true;
 
 
 
@@ -50,7 +60,19 @@ var words3 = [
 
 // Write a function howManyTimes that will take in an array of words as one argument, and a word to search for as the other. The function will return the number of times that word appears in the array.
 
+function howManyTimes(words3, searchItem) {
+  var arr = [searchItem];
+  words3.forEach(element => {
+    if(arr.includes(element)) {
+      arr.push(element);
+    }
+  });
+  return arr.length - 1;
+}
 
+howManyTimes(words3, 'matter'); // 4
+howManyTimes(words3, 'machine'); // 1
+howManyTimes(words3, 'matter-machine'); // 0
 
 
 
@@ -74,6 +96,14 @@ let data = [
   }
 ]
 
+data.reduce((acc, value) => {
+	if (value.country == 'China') {
+		return acc;
+	} else {
+    return acc + value.pop;
+  }
+}, 0);
+
 
 // Use reduce method and summorize the collection like
 // { banana: 2, cherry: 3, orange: 3, apple: 2, fig: 1 }
@@ -91,6 +121,30 @@ const fruitBasket = [
   'fig'
 ];
 
+// var finalObject = {};
+
+// fruitBasket.reduce((acc, value) => {
+//   if (finalObject[acc] == 0) {
+//     finalObject[acc]++;
+//   }
+//   if (!finalObject[value]) {
+//     finalObject[value] = 0;
+//   }
+
+//   finalObject[value]++;
+// }, 0);
+
+// finalObject;
+
+fruitBasket.reduce((acc, value) => {
+  if (acc[value]) {
+    acc[value]++;
+  } else {
+    acc[value] = 1;
+  }
+  return acc;
+}, {});
+
 
 
 // Bonus Question (Solve only if you have time)

array-methods/4-array.js

@@ -31,11 +31,36 @@ var data = [
 
 // your code goes here
 
+var sum = 0;
+function sumDogAge() {
+  for (var i = 0; i < data.length; i++) {
+    if (data[i].type == 'dog') {
+      sum += data[i].age * 7;
+    }
+  }
+}
+
+sumDogAge(); // 105
+
 // Solution is 105
 
+
 // Write the same function using
 // 1. filter - for filtering the cat or dog
 // 2. map - to multiply human year to dog year
 // 3. reduce - to accumulate total age.
 
+// Solution 105
+
+function sumDogAge() {
+  var typeDog = data.filter(element => element.type == 'dog');
+  var dogYear = typeDog.map(element => element.age * 7);
+  var sum = dogYear.reduce((x, y) => x + y);
+
+  return sum;
+}
+
+sumDogAge();
+
+
 // Solution 105

array-methods/5-object.js

@@ -1,6 +1,8 @@
 // 1. Write a JavaScript program to list the properties and values of a JavaScript object. (Object.keys)
 
-
+function listKeyValues(obj) {
+  Object.entries(obj);
+}
 
 // 2. Write a JavaScript program to delete the rollno property from the following object. Also print the object before or after deleting the property.
 var student = { 
@@ -9,7 +11,15 @@ var student = {
   rollno : 12
 };
 
+function deleteRollNo (obj) {
+  delete obj.rollno;
+  console.log(obj);
+}
+deleteRollNo(student);
 
 
-
-// 3. Write a function to get the length of an object.
+// 3. Write a function to get the length of an object.
+function objLen(obj) {
+  return Object.keys(obj).length;
+}
+objLen(student);