Choose a random text from string.xml

Question

I have a string.xml file full of text_1 ... text_100 Now I want to choose a random text of these and display it on a TextView. I tried to use

String text = "text_";
int randomNum = rand.nextInt((100 + 1) + 1;
text = text + String.valueOf(randomNum);
txt.setText(getString(R.string.text);

so now it doesn't work because there is no "text" in the string file...

maybe some suggestions?

`getString()` wants an id. You need to retrieve the string ids from the resource file. — Phantômaxx, Aug 28 '17 at 12:03
@ModularSynth and how can I get a random text out of the file? — MrMinemeet, Aug 28 '17 at 12:05
You can retrieve the resource id from its name. It's been asked a bazillion of times. Please google for it. — Phantômaxx, Aug 28 '17 at 12:06

score 0 · Accepted Answer · answered Aug 28 '17 at 12:15

You can use this, but it is bad practise:

public static int getResId(String resName, Class<?> c) {
    try {
        Field idField = c.getDeclaredField(resName);
        return idField.getInt(idField);
    } catch (Exception e) {
        e.printStackTrace();
        return -1;
    } 
}

In your case:

getResId(text, String.class);

Better option is to create array of strings in xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="planets_array">
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>
        <item>Mars</item>
    </string-array>
</resources>

and then:

String[] planets = res.getStringArray(R.array.planets_array);
int randomNum = rand.nextInt(planets.size() - 1);
txt.setText(planets[randomNum]);

Francis Nduba Numbi · Answer 2 · 2017-08-28T12:48:54.333

You don't just come up with an int id like that. Since you know the resource name, use this method of Resources.class : getIdentifier(resIdName, resTypeName, packageName)

As Resources belongs to Context, you do:

String text = "text_";
 int randomNum = rand.nextInt((100 + 1) + 1; 
text = text + String.valueOf(randomNum);
int textId = getResources().getIdentifier(text, "string", getPackageName());
txt.setText(getString(textId));

There you have the resource id of the item in your string resource.

It was answered here

Choose a random text from string.xml

2 Answers2