switch statement (programming) (Or case statement, multi-way branch) A construct found in most high-level languages for selecting one of several possible blocks of code or branch destinations depending on the value of an expression. An example in C is
switch (foo(x, y)) { case 1: printf("Hello
"); /* fall through */ case 2: printf("Goodbye
"); break; case 3: printf("Fish
"); break; default: fprintf(stderr, "Odd foo value
"); exit(1); } The break statements cause execution to continue after the whole switch statemetnt. The lack of a break statement after the first case means that execution will fall through into the second case. Since this is a common programming error you should add a comment if it is intentional. If none of the explicit cases matches the expression value then the (optional) default case is taken. A similar construct in some functional languages returns the value of one of several expressions selected according to the value of the first expression. A distant relation to the modern switch statement is Fortran's computed goto. Last updated: 1997-01-30
