# Types

To write formulas, you need to be aware of the concept of types. Expressions (constants, variables, parameters, etc.) in formulas can have different types. There are five different built-in types. The following table shows each built-in type and explains its use.

 bool Boolean expressions can only have two values: true or false. This type is returned when expressions are compared: 3 < 4 ; true false == true ; false int Integers are useful for counting. They can have values from -2147483648 to 2147483647. Most arithmetic operations can be performed on integers. Example: 3 -2 float Floating-point numbers are the most familiar type of numbers. They can be very small or large, and have virtually unlimited precision (see Arbitrary precision). Their greatest benefit is that they can represent fractional values. Examples: 3.1 -2.9 1.3e7 complex Complex expressions represent complex numbers. They consist of two floating-point numbers and are used to perform complex arithmetic, which is very useful for fractal calculations. Examples: (2.8, 4) 2.8 + 4i color Color expressions represent a color. You can perform operations on colors and store them in color variables. Internally, a color is stored as four floating-point values, corresponding to red, green, blue, and alpha (opacity) components. Each value ranges from 0 to 1. Colors are intended only for direct coloring algorithms.

Note: You can add new types yourself by declaring classes. This is not necessary when you are beginning to write formulas, though.

Next: Constants