TA exam

problems/countNumbers.js

@@ -1,4 +1,3 @@
-
 /** 
  * Count all the numbers in an array
  * 
@@ -12,8 +11,19 @@
  * returns { 99: 2, 11: 1, 12: 1, 13: 1, 58: 1 }
  */
 
-function countNumbers() {
-
+function countNumbers(arr) {
+    let countNum = {}
+
+    arr.forEach((arr) => {
+        if (countNum[arr]) {
+            countNum[arr] = countNum[arr] + 1
+        } else {
+            countNum[arr] = 1
+        }
+    })
+
+    return countNum
+
 }
 
 

problems/getCountriesSortedByPopulation.js

@@ -10,8 +10,11 @@
 * 
 */
 
-function getCountriesSortedByPopulation() {
+function getCountriesSortedByPopulation(arr) {
+
+    return arr
 
 }
 
-module.exports = getCountriesSortedByPopulation
+
+module.exports = getCountriesSortedByPopulation

problems/isOdd.js

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

problems/numberOfDigits.js

@@ -7,8 +7,11 @@
 
 */
 
-function numberOfDigits() {
+function numberOfDigits(n) {
+    if (n === 0)
+        return 0
+    return n.toString().length
 
 }
 
-module.exports = numberOfDigits
+module.exports = numberOfDigits

problems/removeEvenStrings.js

@@ -19,8 +19,21 @@
 * returns: []
 */
 
-function removeEvenStrings() {
+function removeEvenStrings(arr) {
 
+    //     let newArray = arr.filter((arr) => {
+    //         return arr % 2 === 0
+    //     })
+    //     return newArray
+    // };
+
+    let even = ['']
+    for (let i = 0; i < arr.length; i++) {
+        if (arr[i] % 2 === 0) {
+            even.push(arr[i])
+        }
+    }
+    return arr
 }
 
-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() {
+ * 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) {
 
+    for (let i = 0; i < arr.length; i++) {
+        arr.splice(i + 1, 1)
+    }
+
+    return arr
 }
 
 module.exports = removeNumbersAtOddIndices

problems/removeOddNumbers.js

@@ -1,21 +1,25 @@
 /** Takes an array of numbers and returns a new array.
-* The returned array contains only the even numbers from the input array,
-* with no odd numbers.
-* 
-* @param {number[]} arr - The input array
-* @returns {number[]} - The input array with all odd number removed
-*
-* ex: removeOddNumbers([3, 5, 7, 2, 4, 9, 11, 6]);
-* returns: [2, 4, 6]
-*
-* ex: removeOddNumbers([1, 3, 5])
-* returns: []
-*
-* ex: removeOddNumbers([2, 4, 6])
-* returns: [2, 4, 6]
-*/
-function removeOddNumbers() {
+ * The returned array contains only the even numbers from the input array,
+ * with no odd numbers.
+ * 
+ * @param {number[]} arr - The input array
+ * @returns {number[]} - The input array with all odd number removed
+ *
+ * ex: removeOddNumbers([3, 5, 7, 2, 4, 9, 11, 6]);
+ * returns: [2, 4, 6]
+ *
+ * ex: removeOddNumbers([1, 3, 5])
+ * returns: []
+ *
+ * ex: removeOddNumbers([2, 4, 6])
+ * returns: [2, 4, 6]
+ */
+function removeOddNumbers(arr) {
+    let newArr = arr.filter((num) => {
+        return num % 2 === 0
+    })
+    return newArr
+};
 
-}
 
 module.exports = removeOddNumbers

problems/removeVowels.js

@@ -1,21 +1,31 @@
 /**
-* 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 i = 0
+    let empty = ''
+    while (i < str.length) {
+        if ((str[i] !== 'a') && (str[i] !== 'e') && (str[i] !== 'i') && (str[i] !== 'o') && (str[i] !== 'u')) {
+            if ((str[i] !== 'A') && (str[i] !== 'E') && (str[i] !== 'I') && (str[i] !== 'O') && (str[i] !== 'U')) {
+                empty = empty + str[i]
+            }
+        }
+        i++
+    }
+    return empty
 }
 
-module.exports = removeVowels
+module.exports = removeVowels

problems/sevenBoom.js

@@ -1,18 +1,16 @@
 /** Write a function that returns all the values from 1 to n inclusive, replacing all numbers that are a multiple of seven, or contain seven with "BOOM".
-*
-* @param {number} n - The number to count up to
-* @returns {number[]} - An array matching the pattern described above
-*
-* ex: sevenBoom(20)
-* returns: [1,2,3,4,5,6,'BOOM',8,9,10,11,12,13,'BOOM',15,16,'BOOM',18,19,20]
-* Notice:
-* 7 is replaced with 'BOOM' because it is a multiple of 7 (7 * 1 = 7) AND it contains a 7.
-* 14 is replaced with 'BOOM' because it is a multiple of 7 (7 * 2 = 14)
-* 17 is also replaced with 'BOOM' because it contains a 7.
-*/
+ *
+ * @param {number} n - The number to count up to
+ * @returns {number[]} - An array matching the pattern described above
+ *
+ * ex: sevenBoom(20)
+ * returns: [1,2,3,4,5,6,'BOOM',8,9,10,11,12,13,'BOOM',15,16,'BOOM',18,19,20]
+ * Notice:
+ * 7 is replaced with 'BOOM' because it is a multiple of 7 (7 * 1 = 7) AND it contains a 7.
+ * 14 is replaced with 'BOOM' because it is a multiple of 7 (7 * 2 = 14)
+ * 17 is also replaced with 'BOOM' because it contains a 7.
+ */
 
-function sevenBoom() {
-
-}
+function sevenBoom() {}
 
 module.exports = sevenBoom

problems/smallest.js

@@ -1,21 +1,23 @@
 /**
-* Return the smallest number in an array of numbers.
-*
-* @param {number[]} arr - The input array of numbers
-* @returns {number} - Returns smallest number
-*
-* ex: smallest([3, 0])
-* returns 0
-*
-* ex: smallest([1, -1, 1, 1, 1])
-* returns -1
-*
-* ex: smallest([1, 1, 2])
-* returns 1 (does not matter if it is the first or second 1)
-*/
+ * Return the smallest number in an array of numbers.
+ *
+ * @param {number[]} arr - The input array of numbers
+ * @returns {number} - Returns smallest number
+ *
+ * ex: smallest([3, 0])
+ * returns 0
+ *
+ * ex: smallest([1, -1, 1, 1, 1])
+ * returns -1
+ *
+ * ex: smallest([1, 1, 2])
+ * returns 1 (does not matter if it is the first or second 1)
+ */
+
+function smallest(arr) {
+
+    return Math.min.apply(Math, arr)
 
-function smallest() {
-
 }
 
-module.exports = smallest
+module.exports = smallest