15. Booleans

Boolean variables are perhaps the simplest and can hold a value of either true or false.

def truth = true
def lies = false

Useful Methods

Booleans have a small number of methods that you generally won’t find yourself using as they (mostly) have equivalent operators that are more “natural” to read and write.

The and(right) method performs a logical ‘and’

def truth = true
def lies = false
assert truth.and(lies) == false

The conditional And operator (&&) is equivalent to the and method and the assertion above could also be written as assert truth && lies == false

The or(right) method performs a logical ‘or’

def truth = true
def lies = false
assert truth.or(lies) == true

The conditional Or operator (||) is equivalent to the or method and the assertion above could also be written as assert truth || lies == true