What is Ruby - Interactive Quiz & Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print "Hello, Ruby!".

Ruby

puts [1]

Drag options to blanks, or click blank then click option'

A'Hello Ruby'

BHello, Ruby!

C"Hello, Ruby!"

DHello Ruby

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the text.

Using puts without quotes for strings.

In Ruby, to print text, you use puts with the text inside quotes.

2fill in blank

medium

Complete the code to assign the number 10 to variable x.

Ruby

x = [1]

Drag options to blanks, or click blank then click option'

A"10"

Bten

Cx

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Putting numbers inside quotes makes them strings.

Using variable name instead of value.

In Ruby, to assign a number, write the number without quotes.

3fill in blank

hard

Fix the error in the code to add 5 to variable y.

Ruby

y = 7
sum = y [1] 5

Drag options to blanks, or click blank then click option'

A+

B-

C*

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using - instead of + changes the operation.

Using * or / does multiplication or division.

Use + to add numbers in Ruby.

4fill in blank

hard

Fill both blanks to create a hash with keys as symbols and values as strings.

Ruby

person = { [1]: [2] }

Drag options to blanks, or click blank then click option'

A:name

B"Alice"

C"Bob"

D:age

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings as keys without colon.

Not quoting string values.

In Ruby, hash keys can be symbols like :name, and values can be strings like "Alice".

5fill in blank

hard

Fill all three blanks to define a method that returns the square of a number.

Ruby

def [1](num)
  return num [2] num
end

result = [3](4)

Drag options to blanks, or click blank then click option'

Asquare

B*

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of * for multiplication.

Calling method with wrong name.

Define method 'square', multiply num by num, then call square(4).

Practice

1. What is Ruby primarily known as?

easy

A. A type of database

B. A programming language

C. A web browser

D. An operating system

Solution

1. Step 1: Understand Ruby's category

   Ruby is a tool used to write instructions for computers, which means it is a programming language.

2. Step 2: Eliminate other options

   It is not a database, browser, or operating system, so those options are incorrect.

3. Final Answer:

   A programming language -> Option B

4. Quick Check:

   Ruby = programming language [OK]

Hint: Ruby is a language to tell computers what to do [OK]

Common Mistakes:

• Confusing Ruby with a database
• Thinking Ruby is software like a browser
• Mixing Ruby with operating systems

2. Which of the following is the correct way to print "Hello" in Ruby?

easy

A. print("Hello")

B. echo "Hello";

C. console.log("Hello")

D. printf("Hello")

Solution

1. Step 1: Identify Ruby's print syntax

   Ruby uses the method print() to show text on the screen.

2. Step 2: Check other options for language mismatch

   echo is from PHP, console.log is JavaScript, printf is C-style but less common in Ruby for simple output.

3. Final Answer:

   print("Hello") -> Option A

4. Quick Check:

   Ruby print syntax = print("Hello") [OK]

Hint: Ruby uses print() to show text [OK]

Common Mistakes:

• Using echo instead of print
• Using console.log from JavaScript
• Confusing printf with print

3. What will the following Ruby code output?

puts "Ruby" + " is fun"

medium

A. Ruby is fun

B. Ruby+ is fun

C. nuf si ybuR

D. Error

Solution

1. Step 1: Understand string concatenation in Ruby

   The + operator joins two strings together without extra characters.

2. Step 2: Understand puts output

   puts prints the string and adds a new line automatically, but the output shown is the text without showing the newline character.

3. Final Answer:

   Ruby is fun -> Option A

4. Quick Check:

   "Ruby" + " is fun" = "Ruby is fun" [OK]

Hint: Plus (+) joins strings in Ruby [OK]

Common Mistakes:

• Thinking + adds a plus sign
• Confusing puts with print
• Expecting an error from string addition

4. Find the error in this Ruby code:

puts "Hello World

medium

A. No error, code is correct

B. Missing parentheses after puts

C. puts should be capitalized

D. Missing closing double quote

Solution

1. Step 1: Check string syntax

   The string starts with a double quote but does not have a closing double quote.

2. Step 2: Verify other syntax parts

   Parentheses are optional in Ruby for puts, and puts is lowercase by convention, so no error there.

3. Final Answer:

   Missing closing double quote -> Option D

4. Quick Check:

   Unclosed string causes syntax error [OK]

Hint: Always close your quotes in strings [OK]

Common Mistakes:

• Forgetting to close quotes
• Thinking parentheses are mandatory
• Capitalizing puts incorrectly

5. You want to create a simple Ruby program that prints each word from an array on a new line. Which code correctly does this?

hard

A. words = ("Ruby", "is", "fun")
for word in words puts word end

B. words = ["Ruby", "is", "fun"]
print words.join("\n")

C. words = ["Ruby", "is", "fun"]
words.each { |word| puts word }

D. words = {"Ruby", "is", "fun"}
words.each do |word|
print word
end

Solution

1. Step 1: Identify correct array syntax

   words = ["Ruby", "is", "fun"] words.each { |word| puts word } uses square brackets [] to create an array, which is correct in Ruby.

2. Step 2: Check iteration and printing method

   words = ["Ruby", "is", "fun"] words.each { |word| puts word } uses each with a block and puts to print each word on a new line, which is the correct approach.

3. Final Answer:

   words = ["Ruby", "is", "fun"]\nwords.each { |word| puts word } -> Option C

4. Quick Check:

   Array + each + puts = print words line by line [OK]

Hint: Use array.each with puts to print each item [OK]

Common Mistakes:

• Using parentheses instead of brackets for arrays
• Using print instead of puts for new lines
• Using curly braces for arrays