Ternary operator in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the ternary operator in Ruby?

The ternary operator is a short way to write an if-else statement. It uses the syntax: condition ? true_value : false_value.

beginner

How does the ternary operator work in Ruby?

It checks the condition before the ?. If true, it returns the value after ? and before :. If false, it returns the value after :.

beginner

Rewrite this if-else using a ternary operator:<br>

if age >= 18
  status = 'adult'
else
  status = 'minor'
end

status = age >= 18 ? 'adult' : 'minor'

intermediate

Can the ternary operator be nested in Ruby?

Yes, you can nest ternary operators, but it can make code hard to read. It's better to use if-else for complex conditions.

beginner

What is a common use case for the ternary operator?

It is used for simple decisions to assign a value quickly without writing multiple lines of if-else statements.

What does this Ruby code return?<br>

5 > 3 ? 'yes' : 'no'

A 'no'

B 5

C 'yes'

D 3

Since 5 is greater than 3, the condition is true, so it returns 'yes'.

Which symbol separates the true and false parts in a ternary operator?

A ?

B !

C ;

D :

The colon ':' separates the true part (after '?') and the false part.

What is the output of this code?<br>

puts (10 == 10 ? 'Equal' : 'Not equal')

A Not equal

B Equal

C 10

D Error

10 == 10 is true, so it prints 'Equal'.

Is this a valid ternary operator usage in Ruby?<br>

result = condition ? do_something : do_something_else

A Yes, it's valid

B No, syntax error

C Only if condition is true

D Only if condition is false

This is the correct syntax for a ternary operator.

Why might you avoid nesting ternary operators?

A They make code hard to read

B They run slower

C They cause syntax errors

D They are not supported in Ruby

Nesting ternary operators can make code confusing and hard to maintain.

Explain how the ternary operator works in Ruby and give a simple example.

Think of it as a short if-else in one line.

Describe a situation where using a ternary operator is better than an if-else statement.

When you want to assign a value quickly based on a condition.