Copy LinkCopied!Boolean Expressions

A boolean expression is any expression that produces one of two particular values called boolean values: true or false.

A boolean expression can result from a comparison or a function call. For example, the comparison 10 < 5 ("Is 10 smaller than 5?") is a boolean expression. When the computer reads this, it runs the comparison and produces the value false because 10 is not smaller than 5.

Here are more examples of comparisons with numbers:

• 3 > 0 produces the value true, because 3 is greater than 0.
• '20 == 10produces the valuefalse, because 20is not equal to10`.
• '10 == 10produces the valuetrue, because 10is equal to10`.

We can make boolean expressions with any value type. For example, strings or vectors:

• "hello" == "Hello" produces the value false because one of the two pieces of text starts with a capital letter and the other does not.
• "Godot" == "Godot" produces the value true because both pieces of text are exactly the same.
• Vector2(1,1) == Vector2(1,1) produces the value true because both vectors are the same.

All these examples use values directly (numbers, strings, vectors...), but you can use variables instead, as variables are a way to label a value:

var health = 3
if health == 0:
    die()

Because health has a value of 3 in this example, the boolean expression health == 0 ("is health equal to 0?") is equivalent to writing 3 == 0. As the value of a variable can change, however, in practice, we can use variables to make dynamic comparisons.