final exam

problems/countNumbers.js

@@ -1,20 +1,27 @@
-
-/** 
+/**
  * Count all the numbers in an array
- * 
+ *
  * @param {number[]} arr - An array containing numbers
  * @returns {object} - an object where the key is the number, and the value is the count of that number
- * 
- * ex: countNumbers([1,1,1,2,2,3,4]) 
+ *
+ * ex: countNumbers([1,1,1,2,2,3,4])
  * returns { 1:3, 2:2, 3:1, 4:1 }
- * 
+ *
  * ex: countNumbers([99, 99, 11, 12, 13, 58])
  * returns { 99: 2, 11: 1, 12: 1, 13: 1, 58: 1 }
  */
 
-function countNumbers() {
-
+function countNumbers(arr) {
+  let count = {};
+  for (i = 0; i < arr.length; i++) {
+    let el = arr[i];
+    if (count[el]) {
+      count[el] += 1;
+    } else {
+      count[el] = 1;
+    }
+  }
+  return count;
 }
 
-
-module.exports = countNumbers
+module.exports = countNumbers;

problems/getCountriesSortedByPopulation.js

@@ -10,8 +10,9 @@
 * 
 */
 
-function getCountriesSortedByPopulation() {
+function getCountriesSortedByPopulation(arr) {
+return arr.sort((country1, country2) => country1.population < country2.population ? 1 :-1).map(el => el.country) 
 
 }
 
-module.exports = getCountriesSortedByPopulation
+module.exports = getCountriesSortedByPopulation;

problems/isOdd.js

@@ -9,8 +9,11 @@
 * ex: isOdd(75); // true
 */
 
-function isOdd() {
-
+function isOdd(n) {
+    if (n % 2 === 1 || n % 2 === -1) {
+        return true
+     } else
+        return false
 }
 
 module.exports = isOdd

problems/numberOfDigits.js

@@ -7,8 +7,14 @@
 
 */
 
-function numberOfDigits() {
-
+function numberOfDigits(n) {
+  let digitSum = 0;
+  if (n >= 1)
+  digitSum ++
+  while (n / 10 >= 1) {
+      n /= 10;
+      digitSum ++
+  }
+  return digitSum
 }
-
-module.exports = numberOfDigits
+module.exports = numberOfDigits;

problems/removeEvenStrings.js

@@ -19,8 +19,12 @@
 * returns: []
 */
 
-function removeEvenStrings() {
-
+function removeEvenStrings(arr) {
+  newArr = [];
+  for (let i = 0; i <= arr.length; i += 2) {
+    arr.splice(i % 2)
+  }
+  return newArr
 }
 
-module.exports = removeEvenStrings
+module.exports = removeEvenStrings;

problems/removeNumbersAtOddIndices.js

@@ -1,17 +1,22 @@
-/** Takes an array of numbers and returns a new array 
-* with only the numbers at odd indices in the input array. 
-* 
-* @param {number[]} arr - The input array
-* @returns {number[]} - An array removing all elements initially appearing at an odd index
-*
-* ex: removeNumbersAtOddIndices([0, 1, 2, 3, 4]);
-* returns: [0, 2, 4]
-*
-* ex: removeNumbersAtOddIndices([5, 4, 3, 2, 1]);
-* returns: [5, 3, 1]
-*/
-function removeNumbersAtOddIndices() {
-
+/** Takes an array of numbers and returns a new array
+ * with only the numbers at odd indices in the input array.
+ *
+ * @param {number[]} arr - The input array
+ * @returns {number[]} - An array removing all elements initially appearing at an odd index
+ *
+ * ex: removeNumbersAtOddIndices([0, 1, 2, 3, 4]);
+ * returns: [0, 2, 4]
+ *
+ * ex: removeNumbersAtOddIndices([5, 4, 3, 2, 1]);
+ * returns: [5, 3, 1]
+ */
+function removeNumbersAtOddIndices(arr) {
+  let numsCopy = [];
+  for (let i = 0; i <= arr.length - 1; i++)
+    if (arr[i] % 2 === 0) {
+      numsCopy.push(arr[i]);
+    }
+  return numsCopy;
 }
 
-module.exports = removeNumbersAtOddIndices
+module.exports = removeNumbersAtOddIndices;

problems/removeOddNumbers.js

@@ -14,8 +14,13 @@
 * ex: removeOddNumbers([2, 4, 6])
 * returns: [2, 4, 6]
 */
-function removeOddNumbers() {
-
+function removeOddNumbers(arr) {
+    let numsCopy = [];
+    for (let i = 0; i <= arr.length - 1; i++)
+      if (arr[i] % 2 === 0) {
+        numsCopy.push(arr[i]);
+      }
+    return numsCopy;
 }
 
 module.exports = removeOddNumbers

problems/removeVowels.js

@@ -1,21 +1,28 @@
 /**
-* Removes all vowels from an input string. 
-* For this problem, treat y as a consonant, not a vowel.
-* Vowels are "a", "e", "i", "o", and "u" (upper and lowercase)
-*
-* @param {string} str - The input string
-* @returns {string} - Returns a new string without any vowels.
-*
-* ex: removeVowels("HELLO")
-* returns: "HLL"
-*
-* ex: removeVowels("Sunny")
-* returns: "Snny"
-*
-*/
-
-function removeVowels() {
+ * Removes all vowels from an input string.
+ * For this problem, treat y as a consonant, not a vowel.
+ * Vowels are "a", "e", "i", "o", and "u" (upper and lowercase)
+ *
+ * @param {string} str - The input string
+ * @returns {string} - Returns a new string without any vowels.
+ *
+ * ex: removeVowels("HELLO")
+ * returns: "HLL"
+ *
+ * ex: removeVowels("Sunny")
+ * returns: "Snny"
+ *
+ */
 
+function removeVowels(str) {
+  let noVowels = "";
+  let vowels = "aeiouAEIOU";
+  for (let i = 0; i < str.length; i++) {
+    let letters = str[i];
+    if (!vowels.includes(letters)) {
+      noVowels += letters;
+    }
+  }
+  return noVowels;
 }
-
-module.exports = removeVowels
+module.exports = removeVowels;

problems/sevenBoom.js

@@ -11,8 +11,16 @@
 * 17 is also replaced with 'BOOM' because it contains a 7.
 */
 
-function sevenBoom() {
-
+function sevenBoom(n) {
+    let arr = []
+    for (let i = 1; i < n; i++)
+        if (i % 7 === 0) 
+        arr.push("BOOM")
+        else if (i === 1)
+        arr.push ("BOOM")
+        else
+        arr.push(i)
+        return arr
 }
 
 module.exports = sevenBoom

problems/smallest.js

@@ -14,8 +14,13 @@
 * returns 1 (does not matter if it is the first or second 1)
 */
 
-function smallest() {
-
+function smallest(arr) {
+    let smallest = arr[0];
+    for (let i = 0; i <= arr.length - 1; i++)
+      if (arr[i] < smallest) {
+        smallest = arr[i];
+      }
+    return smallest;
 }
 
 module.exports = smallest