How to use String enums in switch statement?

Question

public class TestingGen {

    /**
     * @param args
     */

    public enum Types {

        TYPE1("TYPE1"), TYPE2("TYPE2");

        private String type;

        private Types(String type) {
            this.type = type;
        }

        public String getType() {
            return type;
        }
    }

    public static void main(String[] args) {

        String value = null;
        switch (value) {
        case Types.TYPE1.getType():
            System.out.println("here");
            break;
        case Types.TYPE2.getType():
            System.out.println("there");
        default:
            System.out.println("default");
        }
    }

}

Its showing errors on both the case statements "case expressions must be constant expressions".

How can I use String enums in swtich statement then ?

[Here is solution](http://stackoverflow.com/questions/10161408/java-using-switch-statement-with-enum-under-subclass) — Volodymyr Levytskyi, Apr 11 '15 at 06:30

score 2 · Answer 1 · answered Apr 11 '15 at 06:28

2

The other way around. Get the enum value for your string Types enumValue = Types.valueOf(stringValue) and switch on the enum values switch(enumValue) { case TYPE1: [...].

answered Apr 11 '15 at 06:28

duckstep

1,148
8
17

Types.valueOf() , gives an exception for invalid values, how to handle that scenario – Vineet Singla Apr 11 '15 at 06:41
Catch the exception, put the `default` case code within the `catch` block. – duckstep Apr 11 '15 at 06:45
hmm... any other way to use enums in swtich – Vineet Singla Apr 11 '15 at 06:47
The string values for the enum values are not constant, they're set during construction of the enum values. Because of that, they can not be used as case expressions. This is by design, I don't know any way around that. – duckstep Apr 11 '15 at 06:57

score -1 · Answer 2 · answered Apr 11 '15 at 06:44

-1

public class TestingGen {

/**
 * @param args
 */

public enum Types {

    TYPE1("TYPE1"), TYPE2("TYPE2");
     String type = null;

    Types(String s) {
        type = s;
    }

     String getType() {
        return type;
    }
}

public static void main(String[] args) {

    for(Types value : Types.values()) { 
        System.out.println(value + "  " + value.getType() + " ");
     }

}

}

answered Apr 11 '15 at 06:44

ajay

477
6
14

I wanted to use enum in swtich case. – Vineet Singla Apr 11 '15 at 06:45

How to use String enums in switch statement?

2 Answers2