OnJava8-Examples/enumerations/OddScoping.java at master · CSapprenticeWT/OnJava8-Examples · GitHub

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// enumerations/OddScoping.java

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// {NewFeature} Since JDK 16

public class OddScoping {

static void f(Object o) {

if(!(o instanceof String s)) {

System.out.println("Not a String");

throw new RuntimeException();

}

// s is in scope here!

System.out.println(s.toUpperCase()); // [1]

}

public static void main(String[] args) {

f("Curiouser and Curiouser");

f(null);

}

/* Output:

CURIOUSER AND CURIOUSER

Not a String

Exception in thread "main" java.lang.RuntimeException

at OddScoping.f(OddScoping.java:8)

at OddScoping.main(OddScoping.java:15)