interrogation-sort.md

Unit 3 - Functional Abstraction with Higher-Order Array Methods

Interrogation: Array.prototype.every and Array.prototype.some

1. Write a function that checks whether all elements of an array are Numbers.

   areAllNumbers([1, 5, 6, 7, '1']);             // false
   areAllNumbers([1, 5, 6, 7, 1]);               // true
   areAllNumbers([1, 5, 6, 7, NaN]);             // false

2. Write a function that takes an array and tests for any prime numbers.

   hasAnyPrimes([123, 11, 8, 3]);  // true 
   hasAnyPrimes([2, 4, 6, 8]);  // false
   hasAnyPrimes([17]);  // true 

3. Write a function that takes an array and tests for any perfect squares.

   hasPerfectSquares([4, 9, 16, 25]); // true
   hasPerfectSquares([2, 10, 50, 75]); // false
   hasPerfectSquares([-4, -9, -16, -25]); // true

Sorting: Array.prototype.sort

4. Write a function that sorts a list of numbers in ascending order.

   ascendingSort([3, 55, 12, 9]); // [3, 9, 12, 55]
   ascendingSort([-33, -50, 1, 0]); // [-50, -33, 0 1]

5. Write a function that sorts an array of first names by alphabetical order.

   alphabeticalOrder(['carl', 'ben', 'amy']); // ['amy', 'ben', 'carl']

6. Write a function that sorts an array of words by the number of vowels in the word.

   sortByVowels(['babe', 'favorite', 'a', 'reader']); // ['a', 'babe', 'reader', 'favorite'];
   sortByVowels(['bob', 'a', 'regular', 'soon']); // ['bob', 'a', 'soon', 'regular'];

7. Write a function that sorts an array of student objects based on their final grades from highest to lowest.

   var studentGrades = [
     { name: 'StudentA', grade: 90.1 },
     { name: 'StudentB', grade: 92 },
     { name: 'StudentC', grade: 91.8 },
     { name: 'StudentD', grade: 95.23 },
     { name: 'StudentE', grade: 91.81 },
   ];
   
   function compareGrades(student1, student2) {
     if (student1.grade < student2.grade) {
       return 1;
     } else if (student1.grade > student2.grade) {
       return -1;
     } else {
       return 0;
     }
   }
   
   studentGrades.sort(compareGrades);
   
   // [{ name: 'StudentD', grade: 95.23 },
   //  { name: 'StudentB', grade: 92 }
   //  { name: 'StudentE', grade: 91.81 },
   //  { name: 'StudentC', grade: 91.8 },
   //  { name: 'StudentA', grade: 90.1 }]
   

Resist the urge to look at the answer until you are finished with all the problems. You can find the answers here