Brainfuck is a minimal language consisting of only eight instructions, a pointer and an array of bytes. At the start of a brainfuck program, the pointer is referencing the first byte of the array. The instructions are all one character long, and the whole set looks like this:
> |
Increment the pointer. |
< |
Decrement the pointer. |
+ |
Increment the byte at the pointer. |
- |
Decrement the byte. |
. |
Output the byte. |
, |
Input a byte and store it at the pointer. |
[ |
If the byte is 0, jump past the matching ] |
] |
Jump to the matching [ |
All other characters should be discarded by the interpreter/compiler. That's brainfuck. The mandatory "hello world" program could look like this, for example:
h ++++++++[>+++++++++++++<-]>. e ---. l +++++++. l . o +++. >+++++[<+++++++++>-]<++++. w >++++[<---------->-]<-. o --------. r +++. l ------. d --------. ! >+++[>+++++++++++<-]>.