Search results
Results From The WOW.Com Content Network
In computer programming languages, a switch statement is a type of selection control mechanism used to allow the value of a variable or expression to change the control flow of program execution via search and map. Switch statements function somewhat similarly to the if statement used in programming languages like C/C++, C#, Visual Basic .NET ...
The switch keyword is used in conjunction with case and default to create a switch statement, which evaluates a variable, matches its value to a specific case (including patterns), and executes the block of statements associated with that case. If no case matches the value, the optional block labelled by default is executed, if included.
In the C programming language, Duff's device is a way of manually implementing loop unrolling by interleaving two syntactic constructs of C: the do-while loop and a switch statement. Its discovery is credited to Tom Duff in November 1983, when Duff was working for Lucasfilm and used it to speed up a real-time animation program.
Switch statements can allow compiler optimizations, such as lookup tables. In dynamic languages, the cases may not be limited to constant expressions, and might extend to pattern matching, as in the shell script example on the right, where the '*)' implements the default case as a regular expression matching any string.
This illustrates an alternative method of specifying the default case, which can appear first, last, or anywhere in between. If no default is specified and no case matches the supplied value, a null value is returned. For each branch of a #switch, either side of an equals-sign "=" can be a simple value, an expression, or a template call.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
a b c Deep breaks may be accomplished in APL, C, C++ and C# through the use of labels and gotos. a Iteration over objects was added in PHP 5. a b c A counting loop can be simulated by iterating over an incrementing list or generator, for instance, Python's range() .
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.