Review

problems/countNumbers.js

@@ -9,9 +9,38 @@
  * returns { 1:3, 2:2, 3:1, 4:1 }
  */
 
-function countNumbers() {
-
+function countNumbers(arr) {
+    const output = {};
+    arr.forEach(el => {
+        if (output[el]) {
+            output[el] += 1;
+        } else {
+            output[el] = 1;
+        }
+        console.log(output)
+    })
+    return output
 }
 
 
+
+
+
+//     let count = {}
+//     for (let i = 0; i < arr.length; i++) {
+//         const el = arr[i];
+//         if (count[el]) {
+//             count[el] += 1
+//         } else {
+//             count[el] = 1;
+
+//         }
+//     }
+
+//     return count;
+
+// }
+
+
+
 module.exports = countNumbers

problems/getCountriesSortedByPopulation.js

@@ -7,8 +7,23 @@
 * 
 */
 
-function getCountriesSortedByPopulation() {
+function getCountriesSortedByPopulation(countries) {
+    countries.sort((country1, country2) => {
 
+        return country2.population - country1.population;
+
+    })
+    return countries.map((country) => {
+
+        return country.country;
+
+
+
+
+    })
 }
 
+
+
+
 module.exports = getCountriesSortedByPopulation

problems/isOdd.js

@@ -7,8 +7,8 @@
 
 */
 
-function isOdd() {
-
+function isOdd(n) {
+    return n % 2 === 1;
 }
 
 module.exports = isOdd

problems/numberOfDigits.js

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

problems/removeEvenStrings.js

@@ -6,8 +6,26 @@
 * @returns {string[]} - Returns the strings in arr that have an odd number of characters
 */
 
-function removeEvenStrings() {
-
+function removeEvenStrings(arr) {
+    const output = arr.filter(el => el.length % 2 === 1)
+    return output;
 }
 
+
+
+// let ouptut = [];
+// for (let i = 0; i < arr.length; i++) {
+//     if (arr[i].length % 2 === 1) {
+//         ouptut.push(arr[i]);
+//     }
+// }
+
+// return ouptut;
+
+
 module.exports = removeEvenStrings
+
+
+//Write down the steps to solve the question
+//Use a sample input
+//Sample output

problems/removeNumbersAtOddIndices.js

@@ -2,8 +2,21 @@
 * @param {number[]} arr - The input array
 * @returns {number[]} - An array removing all elements initially appearing at an odd index
 */
-function removeNumbersAtOddIndices() {
-
+function removeNumbersAtOddIndices(arr) {
+    output = arr.filter((el, index) => !(index % 2));
+    return output;
 }
 
+
+
+
+
+
+// for (i = 0; i < arr.length; i += 2) {
+//     output.push(arr[i]);
+
+// }
+
+
+
 module.exports = removeNumbersAtOddIndices

problems/removeOddNumbers.js

@@ -2,8 +2,19 @@
 * @param {number[]} arr - The input array
 * @returns {number[]} - The input array with all odd number removed
 */
-function removeOddNumbers() {
+function removeOddNumbers(arr) {
 
+    let output = arr.filter((el, index) => !(el % 2));
+
+    // let output = [];
+    // for (let i = 0; i < arr.length; i++) {
+    //     if (arr[i] % 2 === 0) {
+    //         output.push(arr[i]);
+    //     }
+    // }
+    return output;
 }
 
+
+
 module.exports = removeOddNumbers

problems/removeVowels.js

@@ -6,8 +6,16 @@
 * @returns {string} - Returns a new string without any vowels.
 */
 
-function removeVowels() {
+function removeVowels(str) {
+    let arr = str.split("")
+    let out = [];
+    for (let i = 0; i < arr.length; i++) {
+        if (arr[i] !== "o" && arr[i] !== "e" && arr[i] !== "u" && arr[i] !== "i" && arr[i] !== "A" && arr[i] !== "E" && arr[i] !== "I" && arr[i] !== "U" && arr[i] !== "O" && arr[i] !== "a") {
+            out.push(arr[i])
+        }
 
+    }
+    return out.join("")
 }
 
 module.exports = removeVowels

problems/secondSmallest.js

@@ -6,8 +6,31 @@
 * @returns {number} - Returns the second smallest number.
 */
 
-function secondSmallest() {
-
+function secondSmallest(arr) {
+
+
+    // if (arr.length < 2) {
+    //     return null;
+    // }
+    // arr.sort((a, b) => a - b)
+    // return arr[1];
+
+
+    let smallest = Infinity;
+    let secondSmallest = Infinity;
+
+    for (let i = 0; i < arr.length; i++) {
+        const num = arr[i]
+        if (num < smallest) {
+            secondSmallest = smallest
+            smallest = num
+        } else if (num < secondSmallest) {
+            secondSmallest = num
+
+        }
+    }
+    return secondSmallest;
+
 }
 
 module.exports = secondSmallest

problems/sevenBoom.js

@@ -4,8 +4,18 @@
 * @param {number} n - The number to count up to
 * @returns {number[]} - An array matching the pattern described above
 */
-function sevenBoom() {
-
+function sevenBoom(n) {
+    let output = [];
+    for (let i = 1; i <= n; i++) {
+        if (i % 7 === 0 || i.toString().includes("7")) {
+            output.push("BOOM")
+        } else {
+            output.push(i)
+        }
+    }
+    return output;
 }
 
+
+
 module.exports = sevenBoom