Tech test questions

1. Calculate the factorial of a given number

• Input: Integer
• Output: Factorial of the input number
• Example:

  // 5 * 4 * 3 * 2 * 1 = 120
  calculateFactorial(5) => 120

2. Check if a given year is a leap year

• Input: Integer
• Output: Boolean (true if leap year, false otherwise)
• Example:

  isLeapYear(2020) => true

3. Remove duplicate characters from a string

• Input: String
• Output: String with duplicate characters removed
• Example:

  removeDuplicates("hello") => "helo"

4. Check if string is an isogram (no repeating characters)

• Input: String
• Output: Boolean (true if all characters are unique, false otherwise)
• Example:

  hasUniqueCharacters("hello") => false

5. Find the longest word in a sentence

• Input: String (sentence)
• Output: Longest word in the sentence
• Example:

  findLongestWord("This is a sentence.") => "sentence"

6. Calculate the sum of digits in a number

• Input: Integer
• Output: Sum of digits in the number
• Example:

  sumOfDigits(12345) => 15

7. Count the occurrences of each character in a string

• Input: String
• Output: Object mapping characters to their respective counts
• Example:

  countCharacterOccurrences("hello") => { h: 1, e: 1, l: 2, o: 1 }

8. Filter even numbers from an array

• Input: Array of integers
• Output: Array containing only the even numbers
• Example:

  filterEvenNumbers([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) => [2, 4, 6, 8, 10]

9. Find the intersection of two arrays

• Input: Two arrays of integers
• Output: Array containing the common elements of both arrays
• Example:

  findIntersection([1, 2, 3, 4], [3, 4, 5, 6]) => [3, 4]

10. Write a function to flatten nested arrays

• Input: Array containing nested arrays
• Output: Flattened array
• Example:

  const arr = [1, [2, [3, 4], 5], 6];
  flattenArray(arr) => [1, 2, 3, 4, 5, 6]

11. Sort an array of objects by a property value

• Input: Array of objects, property name to sort by
• Output: Array of objects sorted by the specified property value
• Example:

  const people = [
    { name: "John", age: 25 },
    { name: "Jane", age: 30 },
    { name: "Alice", age: 20 }
  ];
  sortByProperty(people, "age") => [
    { name: "Alice", age: 20 },
    { name: "John", age: 25 },
    { name: "Jane", age: 30 }
  ]