I have to write a binary file.
The data is supposed to be written in Little Endian format, which is a type of byte order.
Does anyone know how to do this?

Glossary:

byte order:
byte order sets the endian form of the resulting data. Byte order, or endian form, indicates whether integers are represented in memory from most-significant byte to least-significant byte or vice versa.
little-endian—The least-significant byte occupies the lowest memory address. Used on Windows and Linux.