Statements

Simple statements are complete in themselves; these include assignments, subroutine calls, and a few statements which may significantly affect the program flow of control (e.g. goto, return, stop~/~halt). Some examples include (The following examples loosely follow C syntax):

• assignment: variable = expression
• call: subroutine name(parameters)
• assertion: assert(relational expression)
• goto: goto label
• return: return value
• stop/halt/exit: exit (expression)

Compound statements may contain sequences of statements, nestable to any reasonable depth, and generally involve tests to decide whether or not to obey or repeat these contained statements.

Many compound statements are loop commands or choice commands. Some examples include (The following examples loosely follow C syntax):

• count-controlled loop: for (index = 1; index <= limit; index += 1) <statement>
• condition-controlled loop (test at start): while (test) <statement>
• condition-controlled loop (test at end): do <statement> while (test)
• if statement: if (test) <statement>
• if statement (two-way choice): if (test) <statement> else <statement>
• case/switch statement: switch (c) {case 'a': <statement>; break; case 'b': quit(); break;}
• exception handling: try {protected code} catch (exception specification) {exception handler}