control structure

programming One of the instructions, statements or groups of

statements in a programming language which determines the

sequence of execution of other instructions or statements (the

control flow).

In assembly language this typically consists of jumps and

conditional jumps along with procedure call and return

though some architectures include other constructs such as an

instruction which skips the following instruction depending on

some condition (PDP?), various kinds of loop instructions

(later Motorola 680x0) or conditional execution of all

instructions (Advanced RISC Machine).

Basic control structures (whatever their names in particular

languages) include "if CONDITION then EXPRESSION else

EXPRESSION", the switch statement, "while CONDITION do

EXPRESSION", "gosub", the suspect "goto" and the much-feared

"come from". Other constructs handle errors and

exceptions such as traps and interrupts.

(1997-09-14)