Java Can Switch Strings, Too!

This is probably old news to most of you java devs but in case you didn’t know, as of Java 7 you can use the switch-case construct on a String as well. Evidently, it is more optimized than a regular if-then.

… The Java compiler generates generally more efficient bytecode from switch statements that use String objects than from chained if-then-else statements.

That means that now (haha I said, “now”) you can use:

String something = "whatever";

switch(something) {
    case "whatever":
        doSomeJunk();
        break;

    case "somethingElse":
        whatever();
        break;

    // ...
}

And it will actually out perform a standard if-then:

String something = "whatever";

if (something.equals("whatever")) {
    doSomeJunk();
}
else if (something.equals("somethingElse")) {
    whatever();
}
else if ( /* ... */ ) {
    // ...
}
else if ( /* ... */ ) {
    // ...
}
// ... and so on

Ain’t that great for our hands? Less typing!

Strings in switch statements from the Java 7 documentation provides us with a more practical example:

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;
}