Logical Operators Part 2

Part of the Fundamentals section of Coddy's Ruby journey — lesson 17 of 88.

The ! operator (called "not") flips a boolean value to its opposite. If something is true, applying ! makes it false, and vice versa:

logged_in = true
!logged_in  # false

is_empty = false
!is_empty   # true

This operator is particularly useful when you want to check if something is NOT the case. For example, instead of checking if a user is logged out, you can check if they're "not logged in":

has_permission = false
!has_permission  # true (they do NOT have permission)

You can also combine ! with comparison expressions by wrapping the expression in parentheses:

age = 15
!(age >= 18)  # true (age is NOT 18 or older)

The ! operator is often used to reverse conditions or check for the absence of something, making your logic more readable when you need to express negative conditions.

Challenge

Easy

You are provided with the following variables:

is_raining = true
has_ticket = false
is_member = true
age = 16
balance = 0

Use the ! (not) operator to evaluate and display the following expressions, each on a separate line:

The opposite of is_raining
The opposite of has_ticket
The opposite of is_member
Check if age is NOT greater than or equal to 18 (use ! with parentheses)
Check if balance is NOT equal to 0 (use ! with parentheses)

Each output should be either true or false.

Cheat sheet

The ! operator (called "not") flips a boolean value to its opposite:

logged_in = true
!logged_in  # false

is_empty = false
!is_empty   # true

You can combine ! with comparison expressions by wrapping the expression in parentheses:

age = 15
!(age >= 18)  # true (age is NOT 18 or older)

Try it yourself

# Variables are already defined for you
is_raining = true
has_ticket = false
is_member = true
age = 16
balance = 0

# TODO: Use the ! (not) operator to evaluate and print each expression
# 1. The opposite of is_raining

# 2. The opposite of has_ticket

# 3. The opposite of is_member

# 4. Check if age is NOT greater than or equal to 18

# 5. Check if balance is NOT equal to 0