### 3.1 Built-in Data Types

The standard built-in data types are real and complex scalars and matrices, ranges, character strings, a data structure type, and cell arrays. Additional built-in data types may be added in future versions. If you need a specialized data type that is not currently provided as a built-in type, you are encouraged to write your own user-defined data type and contribute it for distribution in a future release of Octave.

The data type of a variable can be determined and changed through the use of the following functions.

— Built-in Function: class (expr)

> Return the class of the expression expr, as a string.

— Function File: isa (x, class)

> Return true if x is a value from the class class.

— Function File: cast (val, type)

> Convert val to data type type.

> See also: int8, uint8, int16, uint16, int32, uint32, int64, uint64, double.