44 lines
2.1 KiB
Brainfuck
44 lines
2.1 KiB
Brainfuck
[ This program prints "Hello World!" and a newline to the screen, its
|
|
length is 106 active command characters. [It is not the shortest.]
|
|
|
|
This loop is an "initial comment loop", a simple way of adding a comment
|
|
to a BF program such that you don't have to worry about any command
|
|
characters. Any ".", ",", "+", "-", "<" and ">" characters are simply
|
|
ignored, the "[" and "]" characters just have to be balanced. This
|
|
loop and the commands it contains are ignored because the current cell
|
|
defaults to a value of 0; the 0 value causes this loop to be skipped.
|
|
]
|
|
++++++++ Set Cell #0 to 8
|
|
[
|
|
>++++ Add 4 to Cell #1; this will always set Cell #1 to 4
|
|
[ as the cell will be cleared by the loop
|
|
>++ Add 2 to Cell #2
|
|
>+++ Add 3 to Cell #3
|
|
>+++ Add 3 to Cell #4
|
|
>+ Add 1 to Cell #5
|
|
<<<<- Decrement the loop counter in Cell #1
|
|
] Loop till Cell #1 is zero; number of iterations is 4
|
|
>+ Add 1 to Cell #2
|
|
>+ Add 1 to Cell #3
|
|
>- Subtract 1 from Cell #4
|
|
>>+ Add 1 to Cell #6
|
|
[<] Move back to the first zero cell you find; this will
|
|
be Cell #1 which was cleared by the previous loop
|
|
<- Decrement the loop Counter in Cell #0
|
|
] Loop till Cell #0 is zero; number of iterations is 8
|
|
|
|
The result of this is:
|
|
Cell No : 0 1 2 3 4 5 6
|
|
Contents: 0 0 72 104 88 32 8
|
|
Pointer : ^
|
|
|
|
>>. Cell #2 has value 72 which is 'H'
|
|
>---. Subtract 3 from Cell #3 to get 101 which is 'e'
|
|
+++++++..+++. Likewise for 'llo' from Cell #3
|
|
>>. Cell #5 is 32 for the space
|
|
<-. Subtract 1 from Cell #4 for 87 to give a 'W'
|
|
<. Cell #3 was set to 'o' from the end of 'Hello'
|
|
+++.------.--------. Cell #3 for 'rl' and 'd'
|
|
>>+. Add 1 to Cell #5 gives us an exclamation point
|
|
>++. And finally a newline from Cell #6
|
|
|