A Boolean has one of two possible values: true; false. Boolean (logical) operators (and, or, not) take Boolean inputs and yields a Boolean value. Comparison operators on other types (numbers, strings yields a Boolean value.

Block Editor

In the Block Editor, the following blocks represent the true and false Boolean values, which can be plugged in anywhere a Boolean value is expected:
The next three blocks represent the three Boolean (logic) operators:
The next six blocks represent comparison operators that yield a Boolean value. Most comparisons you will do involve numbers:
Boolean values and operators are often used with an if or while statement to determine which code will execute next. For example:

Functions that return a Boolean

Some functions return a Boolean value, which you can store in a Boolean variable. For example, the following code gets the on/off state of point (1, 2) and stores this in the Boolean variable named on. Then the code clears the screen if on is true:

Boolean operators

Boolean operators take Boolean inputs and evaluate to a Boolean output:

Conjunction: A and B

A and B evaluates to true if-and-only-if both A and B are true:
  • false and false = false
  • false and true = false
  • true and false = false
  • true and true = true

Disjunction: A or B

A or B evaluates to true if-and-only-if either A is true or B is true:
  • false or false = false
  • false or true = true
  • true or false = true
  • true or true = true

Negation: not A

not A evaluates to the opposite (negation) of A:
  • not false = true
  • not true = false


This example turns on LED 3 , 3, if LEDs 1 , 1 and 2 , 2 are both on:

Comparisons of numbers and strings

When you compare two Numbers, you get a Boolean value, such as the comparison x < 5 in the code below:
See the documentation on Numbers for more information on comparing two Numbers. You can also compare strings using the equals function.


See also