How can we do switch case using string

Question

public class SwitchExampleString
{
    public static void main(String args[])
    {
        String choice;
        switch(args)
        {
            case "day1" :
                choice="Sunday";
                System.out.println(choice);
                break;
            case "day2" :
                choice="Monday";
                System.out.println(choice);
                break;
            case "day3" :
                choice="Tuesday";
                System.out.println(choice);
                break;
            case "day4" :
                choice="Wednesday";
                System.out.println(choice);
                break;
            case "day5" :
                choice="Thursday";
                System.out.println(choice);
                break;
            case "day6" :
                choice="Friday";
                System.out.println(choice);
                break;
            case "day7" :
                choice="Saturday";
                System.out.println(choice);
                break;
            default :
                System.out.println("Wrong choice");
        }
    }
}

Can anyone help me,i want to know how to use a string inside a switch(). The above shown is the program i had done so far. But it is showing errors. The java version which i have installed is jdk6.

just install jdk7.. java 6 doesn't allow string in switch operation, but from java 7, you can do that. — A N M Bazlur Rahman, Oct 04 '13 at 09:34
possible duplicate of [Switch Statement with Strings in Java](http://stackoverflow.com/questions/338206/switch-statement-with-strings-in-java) — Patrick Kostjens, Oct 04 '13 at 09:35

ppeterka · Accepted Answer · 2013-10-04T09:42:41.147

5

The problem is you are switching on a String array not a String...

switch(args[0])

Would work - given you are using JDK7... And there is an argument supplied to your program - otherwise you'd get a nice ArrayOutOfBoundsException...

edited Oct 04 '13 at 09:42

answered Oct 04 '13 at 09:35

ppeterka

20,583
6
63
78

score 0 · Answer 2 · answered Oct 04 '13 at 09:34

0

Switch with String was introduced in JDK version 7 . So you need to upgrade to jdk7.

answered Oct 04 '13 at 09:34

Juned Ahsan

67,789
12
98
136

May i know the reason of downvote? Op has mentioned the jdk version in use is 6. – Juned Ahsan Oct 04 '13 at 09:40

KhAn SaAb · Answer 3 · 2013-10-04T09:45:33.567

Check your choice or args[0]

public class SwitchExampleString
{

public static void main(String args[])

{
    String choice="day1";
    switch(choice)
    {
case "day1" :
    choice="Sunday";
        System.out.println(choice);
    break;
case "day2" :
    choice="Monday";
        System.out.println(choice);
    break;
case "day3" :
    choice="Tuesday";
        System.out.println(choice);
    break;
case "day4" :
    choice="Wednesday";
        System.out.println(choice);
    break;
case "day5" :
    choice="Thursday";
        System.out.println(choice);
    break;
case "day6" :
    choice="Friday";
        System.out.println(choice);
    break;
case "day7" :
    choice="Saturday";
        System.out.println(choice);
    break;
    default :
System.out.println("Wrong choice");
    }
}

score 0 · Answer 4 · answered Oct 04 '13 at 09:36

You'd need to do it one string from the arguments, not all of them.

switch (args[0]) {
    case "day1" :
       //...

Practically, if you're decoding days you should put that logic in a parsing class -- and probably wouldn't encode them as dayN either. Consider case-insensitivity, as well:

Hopefully that's just your test usecase.. not real design.

With case-insensitivity (forcing to lowercase):

switch (args[0].toLowerCase()) {
    case "day1" :
       //...

score 0 · Answer 5 · answered Oct 04 '13 at 09:36

In the JDK 7 release, you can use a String object in the expression of a switch statement:

public String getTypeOfDayWithSwitchStatement(String dayOfWeekArg) {
     String typeOfDay;
     switch (dayOfWeekArg) {
         case "Monday":
             typeOfDay = "Start of work week";
             break;
         case "Tuesday":
         case "Wednesday":
         case "Thursday":
             typeOfDay = "Midweek";
             break;
         case "Friday":
             typeOfDay = "End of work week";
             break;
         case "Saturday":
         case "Sunday":
             typeOfDay = "Weekend";
             break;
         default:
             throw new IllegalArgumentException("Invalid day of the week: " + dayOfWeekArg);
     }
     return typeOfDay;
}

The switch statement compares the String object in its expression with the expressions associated with each case label as if it were using the String.equals method; consequently, the comparison of String objects in switch statements is case sensitive. The Java compiler generates generally more efficient bytecode from switch statements that use String objects than from chained if-then-else statements.

for more info click here

score 0 · Answer 6 · answered Oct 04 '13 at 09:38

0

strings in switch statements which is recently added feature in Java SE 7.

Using JDK 7, you can pass string as expression in switch statement.

answered Oct 04 '13 at 09:38

Chirag Kathiriya

427
5
14

Dropout · Answer 7 · 2013-10-04T10:24:14.793

You can use switch with String also, however you're trying to use a String array. Pick one argument which you want and use it as the String in the switch.

For example:

String yourChoice = args[0];

switch(yourChoice)
{
    case "something":
        System.out.print("this");
    case "somethingElse":
        System.out.print("that");
}

Also you have to use Java7 or newer and you have to ensure that args[0] isn't null - you have to input an argument when you run your JAR.

score 0 · Answer 8 · answered Oct 04 '13 at 09:39

search on project coin, you will get more info on this. or you can goto simply here: http://java.dzone.com/articles/java-7-%E2%80%93-project-coin-feature dzone, tutorial.

and you can download java 7 from here:http://www.oracle.com/technetwork/java/javase/downloads/index.html

How can we do switch case using string

8 Answers8