2.15. NOP

NOP is a dummy instruction that has no effect. It can be useful as the target of a THEN or ELSE clause.

Example 2.24. Instructions — NOP

Select
  when a=c   then nop           /* Do nothing */
  when a > c then say "A > C"
  otherwise       say "A < C"
end

Note

Putting an extra semicolon instead of the NOP would merely insert a null clause, which would be ignored. The second WHEN clause would be seen as the first instruction expected after the THEN, and would, therefore, be treated as a syntax error. NOP is a true instruction, however, and is, therefore, a valid target for the THEN clause.