Editing Befunge (section)

==Befunge-93 instruction list==
{|
|-----
| width="10%" | <code>0-9</code>
| Push this number onto the stack.
|-----
| <code>+</code>
| Addition: Pop ''a'' and ''b'', then push ''a''+''b''
|-----
| <code>-</code>
| Subtraction: Pop ''a'' and ''b'', then push ''b''-''a''
|-----
| <code>*</code>
| Multiplication: Pop ''a'' and ''b'', then push ''a''*''b''
|-----
| <code>/</code>
| Integer division: Pop ''a'' and ''b'', then push ''b''/''a'', rounded towards 0.
|-----
| <code>%</code>
| Modulo: Pop ''a'' and ''b'', then push the remainder of the integer division of ''b''/''a''. 
|-----
| <code>!</code>
| Logical NOT: Pop a value. If the value is zero, push 1; otherwise, push zero.
|-----
| <code>`</code>
| Greater than: Pop ''a'' and ''b'', then push 1 if ''b''&gt;''a'', otherwise zero.
|-----
| <code>&gt;</code> || Start moving right
|-----
| <code>&lt;</code> || Start moving left
|-----
| <code>^</code> || Start moving up
|-----
| <code>v</code> || Start moving down
|-----
| <code>?</code>
| Start moving in a random cardinal direction
|-----
| <code>_</code>
| Pop a value; move right if value=0, left otherwise
|-----
| <code><nowiki>|</nowiki></code>
| Pop a value; move down if value=0, up otherwise
|-----
| <code>"</code>
| Start string mode: push each character's ASCII value all the way up to the next <code>"</code>
|-----
| <code>:</code> || Duplicate value on top of the stack
|-----
| <code>\</code> || Swap two values on top of the stack
|-----
| <code>$</code> || Pop value from the stack and discard it
|-----
| <code>.</code> || Pop value and output as an integer followed by a space
|-----
| <code>,</code>
| Pop value and output as ASCII character
|-----
| <code>#</code> || Bridge: Skip next cell
|-----
| <code>p</code>
| A "put" call (a way to store a value for later use). Pop ''y'', ''x'', and ''v'', then change the character at (''x'',''y'') in the program to the character with ASCII value ''v''
|-----
| <code>g</code>
| A "get" call (a way to retrieve data in storage). Pop ''y'' and ''x'', then push ASCII value of the character at that position in the program
|-----
| <code>&</code> || Ask user for a number and push it
|-----
| <code>~</code>
| Ask user for a character and push its ASCII value
|-----
| <code>@</code> || End program
|-----
| <code> </code>(space) || [[No-op]]. Does nothing
|}

Most one-dimensional programming languages require some syntactic distinction between [[comment (computer programming)|comment text]] and [[source code]] — although that distinction may be as trivial as [[Brainfuck]]'s rule that any character not in the set <code><nowiki>+-[]<>,.</nowiki></code> is a comment. Languages like [[Lisp (programming language)|Lisp]] and [[Python (programming language)|Python]] treat strings as comments in contexts where the values are not used. Similarly, in Befunge, there is no comment syntax: to embed documentation in the code, the programmer simply routes the control flow ''around'' the "comment" area, so that the text in that area is never executed.