" Using switchCase with null "

Question

I am trying to use message==null and message!=null with switch case , but it gives me syntax error . Here is the code

    String message = "Happy New Year ;)";
switch (message) {
case null :
    break;
case !null :
    System.out.println(message);
    break;
    default :           
}

I've done it with if{}else{} and it has no problem with it , but I don't know what is wrong with switchCase .

   if(message == null) {
     
 }else if (message != null) {
     System.out.println(message);
 }

Thank you for your response ❤

score 3 · Accepted Answer · answered Jan 13 '21 at 18:42

3

Java doesn't support using null in switch statements

Null in switch case Java Java docs clearly stated that: The prohibition against using null as a switch label prevents one from writing code that can never be executed. If the switch expression is of a reference type, such as a boxed primitive type or an enum, a run-time error will occur if the expression evaluates to null at run-time

answered Jan 13 '21 at 18:42

Iñigo Bereciartua

72
1
10

Thanks man , appreciate your answer . – Coder Boy 9O9 Jan 13 '21 at 19:28

Coder · Answer 2 · 2021-01-13T19:13:40.237

1

You cannot do !null in java since null is not of type boolean.

Instead, try checking for it before since you know you will not have entered the else clause if message was null.

String message = "Happy New Year ;)";
if (message == null) {
  // error
}
else {
  switch (message) {
    case x:
      y();
      break;
    default:
      System.out.println(message);
      break;
  }
}

edited Jan 13 '21 at 19:13

answered Jan 13 '21 at 18:42

Coder

1,175
1
12
32

still error , because of the null keyword , but I think I should use the if_statement . – Coder Boy 9O9 Jan 13 '21 at 19:11
1

@TwanaStackoverflow edited! this should work now! – Coder Jan 13 '21 at 19:13

" Using switchCase with null "

2 Answers2