Search results
Results from the WOW.Com Content Network
Switch statements function somewhat similarly to the if statement used in programming languages like C/C++, C#, Visual Basic .NET, Java and exist in most high-level imperative programming languages such as Pascal, Ada, C/C++, C#, [1]: 374–375 Visual Basic .NET, Java, [2]: 157–167 and in many other types of language, using such keywords as ...
Duff realized that to handle cases where count is not divisible by eight, the assembly programmer's technique of jumping into the loop body could be implemented by interlacing the structures of a switch statement and a loop, putting the switch's case labels at the points of the loop body that correspond to the remainder of count/8: [1]
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 glob matching any string.
A combination of state variables and structured control, notably an overall switch statement, can allow a subroutine to resume execution at an arbitrary point on subsequent calls, and is a structured alternative to goto statements in the absence of coroutines; this is a common idiom in C, for example.
Example of branch table in Wikibooks for IBM S/360; Examples of, and arguments for, Jump Tables via Function Pointer Arrays in C/C++; Example code generated by 'Switch/Case' branch table in C, versus IF/ELSE. Example code generated for array indexing if structure size is divisible by powers of 2 or otherwise.
The switch parser function, coded as "#switch", selects the first matching branch in a list of choices, acting as a case statement. Each branch can be a value , an expression ( calculation ), or a template call, [ 1 ] evaluated and compared to match the value of the switch.
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!
If the statements in the loop are independent of each other (i.e. where statements that occur earlier in the loop do not affect statements that follow them), the statements can potentially be executed in parallel. Can be implemented dynamically if the number of array elements is unknown at compile time (as in Duff's device).