Free Ruby Association Ruby-Programmer-Gold Exam Questions

Question 1

Review the following Ruby code snippet:def divide_numbers(x, y) x / yrescue ZeroDivisionError => e puts "Error: #{e.message}"end result1 = divide_numbers(10, 2)result2 = divide_numbers(10, 0)result3 = begin divide_numbers(10, '5') rescue TypeError => e "Caught: #{e.class}" endresult4 = divide_numbers(10, nil) rescue "Invalid operation" What will be the values of result1, result2, result3, and result4, respectively?

A : 5, nil, Caught: TypeError, Invalid operation

B : 5, Error: divided by 0, TypeError, TypeError

C : 5, ZeroDivisionError, Caught: TypeError, Invalid operation

D : 5, Error: divided by 0, Caught: TypeError, Invalid operation

Answer: D

Question 2

In Ruby, which of the following literals correctly creates a Hash object with default values for undefined keys?

A : hash = { default: [] }

B : hash = Hash.new { |h, k| h[k] = [] }

C : hash = Hash[:default, 0]

D : hash = {}.default(0)

Answer: B

Question 3

In Ruby, the use of blocks is a fundamental concept for iterating over collections and executing code repeatedly. Examine the following Ruby code snippet:numbers = [1, 2, 3, 4, 5]sum = 0numbers.each { |number| sum += number }doubled = numbers.map { |number| number * 2 } Based on this code, which two of the following statements are true regarding the use and functionality of blocks?

A : The each block creates a new array with each number in numbers incremented by 1.

B : Both each and map blocks modify the original numbers array.

C : The each block increments sum by each number in the numbers array, resulting in the sum of all elements.

D : The map block modifies the original numbers array to contain each number doubled.

E : The map block returns a new array with each number in numbers doubled, leaving the original array unchanged.

Answer: C,E

Question 4

Review the following Ruby code snippet:def divide_numbers(x, y) x / yrescue ZeroDivisionError => e puts "Error: #{e.message}"end result1 = divide_numbers(10, 2)result2 = divide_numbers(10, 0)result3 = begin divide_numbers(10, '5') rescue TypeError => e "Caught: #{e.class}" endresult4 = divide_numbers(10, nil) rescue "Invalid operation" What will be the values of result1, result2, result3, and result4, respectively?

A : 5, nil, Caught: TypeError, Invalid operation

B : 5, Error: divided by 0, TypeError, TypeError

C : 5, ZeroDivisionError, Caught: TypeError, Invalid operation

D : 5, Error: divided by 0, Caught: TypeError, Invalid operation

Answer: D

Question 5

In Ruby, the understanding of operators and their precedence is crucial for writing correct and efficient code. Consider the following Ruby code snippet:a = 10b = 3result1 = a + b * 2result2 = (a + b) % 3result3 = a ** b / 2 Based on this code, which two of the following statements are true regarding the use of operators and their precedence?

A : result2 calculates the remainder of a + b divided by 3 due to the % operator.

B : result2 equals 1 because parentheses change the order of operations, prioritizing addition over modulo.

C : result1 equals 16 because addition (+) has a higher precedence than multiplication (*).

D : result3 results in 50 because division (/) has a higher precedence than exponentiation (**).

E : In result1, the multiplication (*) is performed before addition (+) due to operator precedence.

Answer: A,E