Using string from resource XML in Switch?

Question

New to Android here, so I apologize if this is a simplistic question.

I am attempting to use a switch based on string resources in my XML. It would look something like this:

switch (myStringVariable) {
    case getResources().getString(R.string.first_string):
         break;
    case getResources().getString(R.string.second_string):
         break;
    case getResources().getString(R.string.third_string):
         break;
    default:
         break;
}

Unfortunately, this won't work. The error that I get is "Constant expression required".

Is there a semi-elegant way to go about this, without having to do something like create 3 String objects and assign the string resources to each object? I feel like I'm missing something obvious, so any assistance would be great!

Thanks :)

Assigning the string objects these values still doesn't work, right? The values are decided at run time, not compile time? — Tyler Pfaff
– Tyler Pfaff, Commented Jun 9, 2015 at 20:27

npace · Accepted Answer · 2015-04-09 15:05:09Z

5

Well, first of all, the version of Java that Android is based on does not support String switch statements, so generally you have to use if/else blocks instead.

EDIT: String switch statements are supported if you use JDK 1.7 and later

I'm not sure what your use case is, but if you have the resource ID of myStringVariable, which is an int, you can do a switch over that:

switch (myStringResId) {
case R.string.first_string:
     break;
case R.string.second_string:
     break;
case R.string.third_string:
     break;
default:
     break;
}

edited Apr 9, 2015 at 15:05

answered Apr 9, 2015 at 14:58

npace

4,2581 gold badge27 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Blackbelt Over a year ago

not support String switch statements, that's not true

npace Over a year ago

Oh wow, thanks for pointing that one out. Last time I tried doing a String switch on android was in 2012 before we could compile with JDK 1.7.

yoAlex5 · Accepted Answer · 2019-11-05 11:47:40Z

4

Well, it's not the most elegant way, but you can use if - else if statements instead of switch - case:

if (myStringVariable.equals(getString(R.string.first_string))) {
    // do something
} else if (myStringVariable.equals(getString(R.string.second_string))) {
    // do something
} else if (myStringVariable.equals(getString(R.string.third_string))) {
    // do something
}

edited Nov 5, 2019 at 11:47

yoAlex5

35.2k10 gold badges235 silver badges255 bronze badges

answered Aug 18, 2015 at 8:56

harryr

414 bronze badges

Comments

Community · Accepted Answer · 2017-05-23 12:34:04Z

3

You're not missing something Android-related but Java-related instead.

Check this answer about how Java manages the Switch statement:

https://stackoverflow.com/a/3827424/2823516

You'll have to use the non elegant solution you mentioned. But who says is not elegant? Is what you should do, and that makes it elegant.

edited May 23, 2017 at 12:34

CommunityBot

11 silver badge

answered Apr 9, 2015 at 15:01

Joaquin Iurchuk

5,6552 gold badges52 silver badges68 bronze badges

Collectives™ on Stack Overflow

Using string from resource XML in Switch?

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related