ComputeAreaModernIs
NoteThe
No matching tags
No matching tags
Square s
No matching tags
No matching tags
geometric shapes using pattern matching statements. write if statements and switch that test a variable's value. statements:That code above is a classic expression of the type pattern: You're testing a variable value types as well as reference types.Language rules for pattern matching expressions help you avoid misusing of a pattern match expression when that pattern wasn't met.As time goes on, you may need to support other shape types. In this case, you'll find that the switch pattern You could compare a variable to any constant used in a case statement:The only pattern supported by the switch statement was the constant statement using the type pattern:The pattern matching switch statement uses familiar syntax to developers on the type of the variable in the switch expression have been removed. label could match the value of the switch expression. If either of these cases match, clearly one of the variables has been assigned. introduce a new variable in the case statement, or you'll only use the and blocks for each of the new shapes.Finally, you can add a null case to ensure the argument isn't null:The special behavior for the null pattern is interesting because the constant defines that a null value won't match any type pattern, regardless of the they aren't necessary, since matching the type pattern guarantees a non-null value.The introduction of var as one of the match expressions introduces new in a case expression matches the same conditions as a default expression. switch statement behavior where all possible cases have been listed.The third rule introduces uses where a var case may be useful. a var case expression that is distinct from a default expression.Pattern Matching constructs enable you to easily manage control flow Pattern Matching works with any data type. You'll often find that pattern matching expressions can be a very
As said here by BillWagner