4.1 Boolean values

Learning objectives

By the end of this section you should be able to

• Explain a Boolean value.
• Use bool variables to store Boolean values.
• Demonstrate converting integers, floats, and strings to Booleans.
• Demonstrate converting Booleans to integers, floats, and strings.
• Use comparison operators to compare integers, floats, and strings.

bool data type

People often ask binary questions such as yes/no or true/false questions. Ex: Do you like pineapple on pizza? Ex: True or false: I like pineapple on pizza. The response is a Boolean value, meaning the value is either true or false. The bool data type, standing for Boolean, represents a binary value of either true or false. true and false are keywords, and capitalization is required.

Type conversion with bool

Deciding whether a value is true or false is helpful when writing programs/statements based on decisions. Converting data types to Booleans can seem unintuitive at first. Ex: Is "ice cream" True? But the conversion is actually simple.

bool converts a value to a Boolean value, True or False.

• True: any non-zero number, any non-empty string
• False: 0, empty string

Comparison operators

Programmers often have to answer questions like "Is the current user the admin?" A programmer may want to compare a string variable, user, to the string, "admin". Comparison operators are used to compare values, and the result is either true or false. Ex: is_admin = (user == "admin"). user is compared with "admin" using the == operator, which tests for equality. The Boolean variable, is_admin, is assigned with the Boolean result.

The 6 comparison operators:

• equal to: ==
• not equal to: !=
• greater than: >
• less than: <
• greater than or equal to: >=
• less than or equal to: <=