Method naming conventions (? and ! suffixes) in Ruby - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does a method name ending with a ? usually indicate in Ruby?

It indicates that the method returns a boolean value (true or false), often used for predicate methods that ask a question about an object.

beginner

What is the purpose of a method name ending with a ! in Ruby?

It signals that the method is "dangerous" or performs its action in a more surprising or destructive way, often modifying the object in place.

intermediate

Can a method have both ? and ! suffixes in Ruby?

No, Ruby does not allow method names to end with both ? and ! at the same time.

beginner

Why should you use ? suffix only for methods that return boolean values?

Because it helps other programmers understand that the method answers a yes/no question, improving code readability and intention clarity.

intermediate

Give an example of a Ruby method with a ! suffix and explain its behavior.

Example: upcase! modifies the string in place to uppercase letters, unlike upcase which returns a new string without changing the original.

What does a Ruby method ending with ? usually return?

A A boolean value (true or false)

B A modified object

C An error message

D A string

Methods ending with ? are predicate methods that return true or false.

What does the ! suffix in a Ruby method name usually warn about?

A The method is slow

B The method modifies the object or is dangerous

C The method returns a boolean

D The method is deprecated

The ! suffix warns that the method may change the object or behave in a surprising way.

Which of these is a valid Ruby method name?

A dangerous_method!

B valid_method?

C check_method?!

D method!?

Methods can end with either ? or !, but not both or in combination.

Why is it important to follow the ? and ! naming conventions in Ruby?

A To make code run faster

B To make methods private

C To improve code readability and communicate method behavior

D To avoid syntax errors

These suffixes help programmers understand what the method does at a glance.

What does the method empty? typically check in Ruby?

A If a number is zero

B If an object is nil

C If a method is dangerous

D If a collection or string has no elements or characters

empty? returns true if a string or collection has no content.

Explain the difference between Ruby methods ending with ? and those ending with !.

Think about how these suffixes help communicate what the method does.

Why is it helpful to use ? and ! suffixes in method names when writing Ruby code?

Consider how naming conventions affect teamwork and maintenance.