Home Articles FAQs XREF Games Software Instant Books BBS About FOLDOC RFCs Feedback Sitemap
irt.Org

switch statement

You are here: irt.org | FOLDOC | 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\n");	/* fall through */
	case 2:  printf("Goodbye\n"); break;
	case 3:  printf("Fish\n"); break;
	default: fprintf(stderr, "Odd foo value\n"); 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.

(1997-01-30)

Nearby terms: switched virtual connection « switching « switching hub « switch statement » swizzle » SWL » SWT

FOLDOC, Topics, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, ?, ALL

©2018 Martin Webb