Editing Stack-oriented programming (section)

=== Control and flow ===
As there exist anonymous procedures, flow control can arise naturally. Three pieces of data are required for an [[if-then-else]] statement: a condition, a procedure to be done if the condition is true, and one to be done if the condition is false. In PostScript for example,
<syntaxhighlight lang="postscript">

 2 3 gt { (2 is greater than three) = } { (2 is not greater than three) = } ifelse
</syntaxhighlight>
performs the near equivalent in C:
<syntaxhighlight lang="c">
 if (2 > 3) { printf("2 is greater than three\n"); } else { printf("2 is not greater than three\n"); }
</syntaxhighlight>
Looping and other constructs are similar.