Array u0026 String Combined Challenges: Mixed Practice Quiz Quiz

Sharpen your problem-solving skills with this medium-level quiz on combining arrays and strings. Explore essential techniques in manipulating, searching, and transforming arrays and strings, ideal for learners and professionals aiming for mastery in core programming concepts.

1. Find the Longest Word in Mixed Strings

   Given an array of strings like ['cat', 'giraffe', 'lion'], which method efficiently finds the longest word in the array?

   1. Remove all words containing less than four letters
   2. Use the string length of the first element as the answer
   3. Sort the array alphabetically and take the last word
   4. Iterate with a loop, tracking the longest string found so far

   Explanation: The correct approach is to iterate through the array, keeping track of which string has the maximum length. Sorting alphabetically does not guarantee finding the longest word since it only considers character order, not length. Using the length of only the first element ignores the rest of the array and can easily be incorrect. Removing words based on an arbitrary length, such as four letters, may still not leave the true longest word. Therefore, a loop with a maximum tracker is most accurate.

2. Array to Sentence

   How can you convert an array like ['apple', 'banana', 'cherry'] into a single string 'apple, banana, cherry'?

   1. Multiply all elements together
   2. Concatenate each element with a plus '+' operator
   3. Use an array join operation with ', ' as the separator
   4. Use only the first two elements and ignore the rest

   Explanation: Using the join method with ', ' combines all elements of an array into a single string, placing a comma and space between them. The plus '+' operator does not properly separate the elements and can create errors with non-string types. Multiplying elements is not a valid option for string arrays, and using only the first two elements misses parts of the data. Therefore, the join method is the correct and most efficient way.

3. Reversing Words in a Sentence Array

   Given a sentence split into an array of words, such as ['hello', 'world', 'again'], what is the best way to reverse the sentence word order?

   1. Capitalize every word in the array
   2. Take only the first and last words and swap them
   3. Reverse the array and join it back into a string
   4. Sort the array in place

   Explanation: Reversing the array flips the order of words so the sentence reads backwards when joined back. Sorting reorders alphabetically, which is unrelated to sentence structure. Capitalizing every word changes their case but not their order. Swapping only the first and last words does not handle sentences with more than two words. Thus, reversing then joining is the accurate choice.

4. Counting Characters Across Array Strings

   If you need to count the total number of characters across an array like ['hi', 'there'], what approach should you use?

   1. Subtract the shortest string's length from the longest
   2. Return the length of the array as the answer
   3. Sum the length of each string in the array
   4. Multiply the lengths of both strings together

   Explanation: Adding the length of each string gives the total character count across the array. Subtracting only compares two elements and misses the cumulative sum. Multiplying the lengths provides a totally unrelated number. Using the length of the array returns the number of elements, not characters. Summing individual lengths is the most logical and correct method.

5. Detecting Palindromes in an Array of Words

   Given an array like ['level', 'book', 'noon'], which technique helps you find all palindromic words?

   1. Check for vowels in each word
   2. Check if each word equals its reverse
   3. Remove all words shorter than five letters
   4. Sort all words before checking

   Explanation: A palindrome reads the same forward and backward, so comparing a word with its reverse reveals if it qualifies. Sorting words does not aid in identifying palindromes, while searching for vowels is unrelated to word symmetry. Removing words based purely on length will not accurately identify all palindromes, as some may be short. Thus, direct reversal comparison is required to detect palindromes.