Some programming languages provide a complex data type for complex number storage and arithmetic as a built-in (primitive) data type.
A complex variable or value is usually represented as a pair of floating-point numbers.
Languages that support a complex data type usually provide special syntax for building such values, and extend the basic arithmetic operations ('+', '−', '×', '÷') to act on them.
These operations are usually translated by the compiler into a sequence of floating-point machine instructions or into library calls.
Those languages may also provide support for other operations, such as formatting, equality testing, etc.