Using Strings as switch parameter

Question

I read in an article on Switch vs If that if we use String as switch parameter,the compiler will not make a jump table. Is this correct and if yes, pleas explain why?

Thanks

PS

I'm more interested in knowing this regarding java. And the part I read about this is from an answer here in Stackoverflow. So here's the link stackoverflow.com/a/395965/1043937

It says about c#, but since java also has the same feature since 1.7, Can someone please explain.

This issue is very different in Java and C. Please specify which language you meant. — Daniel Kamil Kozar, Jun 22 '12 at 08:12

score 3 · Accepted Answer · edited May 23 '17 at 10:09

3

Switch statements in C cannot accept strings as parameters.

Switch statements on strings in java are available since java 1.7. They weren't before as this block was modeled from the c feature. The fact that java uses, or not, a jump table is implementation dependent and the result also depends on the values.

Edit : for details about the implementation, refer to the link provided by Jon.

edited May 23 '17 at 10:09

Community

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answered Jun 22 '12 at 08:13

Denys Séguret

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score 0 · Answer 2 · edited Jun 22 '12 at 08:16

0

Prior to java 1.7 you can't use string as switch parameter. This is a feature in java 1.7 that you can also use String as switch parameter .

edited Jun 22 '12 at 08:16

Daniel Kamil Kozar

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answered Jun 22 '12 at 08:15

Pramod Kumar

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-1 The question is asking if _the compiler will not make a jump table. Is this correct and if yes, pleas explain why?_ – Kazekage Gaara Jun 22 '12 at 08:17

score 0 · Answer 3 · answered Jun 22 '12 at 08:54

Switch statements work either with primitive types or enumerated types. Java 7 introduced another type that we can use in Switch statements: the String type.

public void process(Trade t) {

        String status = t.getStatus();



        switch (status) {

        case NEW:

              newTrade(t);

              break;

        case EXECUTE:

              executeTrade(t);

              break;

        case PENDING:

              pendingTrade(t);

              break;



        default:

              break;

        }

  }

Using Strings as switch parameter

3 Answers3