C# Language Specification - Willy .Net

C# LANGUAGE SPECIFICATIONvoid DoCommand(string command) {switch (command.ToLower()) {case "run":DoRun();break;case "save":DoSave();break;case "quit":DoQuit();break;default:InvalidCommand(command);break;}}end example][Note: Like the string equality operators (§14.9.7), the switch statement is case sensitive and will execute agiven switch section only if the switch expression string exactly matches a case label constant. end note]When the governing type of a switch statement is string, the value null is permitted as a case labelconstant.The statement-lists of a switch-block may contain declaration statements (§15.5). The scope of a localvariable or constant declared in a switch block is the switch block.Within a switch block, the meaning of a name used in an expression context must always be the same(§14.5.2.1).The statement list of a given switch section is reachable if the switch statement is reachable and at leastone of the following is true:• The switch expression is a non-constant value.• The switch expression is a constant value that matches a case label in the switch section.• The switch expression is a constant value that doesn’t match any case label, and the switch sectioncontains the default label.• A switch label of the switch section is referenced by a reachable goto case or goto defaultstatement.The end point of a switch statement is reachable if at least one of the following is true:• The switch statement contains a reachable break statement that exits the switch statement.• The switch statement is reachable, the switch expression is a non-constant value, and no defaultlabel is present.• The switch statement is reachable, the switch expression is a constant value that doesn’t match anycase label, and no default label is present.15.8 Iteration statementsIteration statements repeatedly execute an embedded statement.iteration-statement:while-statementdo-statementfor-statementforeach-statement15.8.1 The while statementThe while statement conditionally executes an embedded statement zero or more times.186