Programming Fundamentals/Selection Control Structures

Overview In selection control structures, conditional statements perform different computations or actions depending on whether a programmer-specified Boolean condition evaluates to true or false.Wikipedia: Conditional (computer programming) Discussion The basic attribute of a selection control structure is to be able to select between two or more alternate paths. This is described as either two-way selection or multi-way selection. A question using Boolean concepts usually controls which path is selected. All of the paths from a selection control structure join back up at the end of the control structure, before moving on to the next lines of code in a program. If Then Else Control Structure The if then else control structure is a two-way selection. If age > 17 Output "You can vote." False: Output "You can't vote." End LanguageReserved WordsC++if, elseC#if, elseJavaif, elseJavaScriptif, elsePythonif, elif, elseSwiftif, else Case Control Structure The case control structure is a multi-way selection. Case control structures compare a given value with specified constants and take action according to the first expression to match.Wikipedia: Conditional (computer programming) Case of age 0 to 17 Display "You can't vote." 18 to 64 Display "You're in your working years." 65 + Display "You should be retired." End LanguageReserved WordsC++switch, case, break, defaultC#switch, case, break, defaultJavaswitch, case, break, defaultJavaScriptswitch, case, break, defaultPythonN/ASwiftswitch, case, break (optional), default Python does not support a case control structure. There are workarounds, but they are beyond the scope of this book. Key Terms if then else A two-way selection control structure. case A multi-way selection control structure. References cnx.org: Programming Fundamentals – A Modular Structured Approach using C++