1 [ This program prints "Hello World!" and a newline to the screen, its
2 length is 106 active command characters [it is not the shortest.]
3 This loop is a "comment loop", it's a simple way of adding a comment
4 to a BF program such that you don't have to worry about any command
5 characters. Any ".", ",", "+", "-", "<" and ">" characters are simply
6 ignored, the "[" and "]" characters just have to be balanced.
8 +++++ +++ Set Cell #0 to 8
10 >++++ Add 4 to Cell #1; this will always set Cell #1 to 4
11 [ as the cell will be cleared by the loop
16 <<<<- Decrement the loop counter in Cell #1
17 ] Loop till Cell #1 is zero; number of iterations is 4
20 >- Subtract 1 from Cell #4
22 [<] Move back to the first zero cell you find; this will
23 be Cell #1 which was cleared by the previous loop
24 <- Decrement the loop Counter in Cell #0
25 ] Loop till Cell #0 is zero; number of iterations is 8
26 The result of this is:
27 Cell No : 0 1 2 3 4 5 6
28 Contents: 0 0 72 104 88 32 8
30 >>. Cell #2 has value 72 which is 'H'
31 >---. Subtract 3 from Cell #3 to get 101 which is 'e'
32 +++++++..+++. Likewise for 'llo' from Cell #3
33 >>. Cell #5 is 32 for the space
34 <-. Subtract 1 from Cell #4 for 87 to give a 'W'
35 <. Cell #3 was set to 'o' from the end of 'Hello'
36 +++.------.--------. Cell #3 for 'rl' and 'd'
37 >>+. Add 1 to Cell #5 gives us an exclamation point
38 >++. And finally a newline from Cell #6