Develop Reference

Pulling individual strings from string arrays at random

Im trying to pull individual strings from a string array at random, and display it on screen(in android studio). But i cant seem to find a solution anywhere.
Its a simple string array, and i need to pull one at a click of a button. My string array is pretty standard and set up like this:
<string-array name="string_array1">
<item>Sentence 1</item>
<item>Sentence 2</item>
</string-array>

You can user java String array or ArrayList of String in Activity like:
Java String Array Example in Activity :
1)define an Array
String string_array1[]={"Sentence 1","Sentence 2"};
Get value from the array :
Sting zeroIndexValue=string_array1[0];
Sting oneIndexValue=string_array1[1];
2) ArrayList Example:
define ArrayList of String:
ArrayList<String> string_List=new ArrayList<String>();
Add value to List:
string_List.add("Sentence 1");
string_List.add("Sentence 2");
Get value from List:
string_List.get(0);
string_List.get(1);

fetch array from string file
String[] string_array1 = getResources().getStringArray(R.array.string_array1);
Now generate random value and fetch it from array.
Random rand = new Random()
int Low = 0;
int High = string_array1.length-1;
int value = rand.nextInt(High-Low) + Low; //It will generate random number in the given range only.
String printed_value = string_array1[value];

Increment hex value of R.id file element

i have some consecutive elements id declared inside R.java files. Now i need to fill each one by using a for cycle, so i need to increment for each iteration value of id. I've write this:
int current_id = R.id.button00;
for (int i = 0; i < values.length; i++) {
TextView to_fill = (TextView) (getActivity().findViewById(current_id));
to_fill.setText(String.valueOf(values[i]));
current_id++;
}
but in this way current_id doesn't increment correctly.
How can i do?

There is no guarantee that the generated IDs in R will be sequential, or that they will be generated in any particular order.
I recommend putting your IDs in an array resource like so:
<array name="button_id_array">
<item>#id/button00</item>
<item>#id/button01</item>
<item>#id/button02</item>
</array>
Then you can access it in code like so:
int[] ids = getResources().getIntArray(R.array.test);

get list of the strings present in strings.xml file in Android

I want the list of strings present in the strings.xml file.
Does anyone knows how to get it??? One thing I found is it assigns the ids in sequential order inside R.java but how to get the starting id is not clear.
For Example I have 100 Strings in my strings.xml like below and I want to read in at a time not like giving getResources().getString(int id) for individual.
<string name="app_label">Calendar</string>
<string name="what_label">What</string>
<string name="where_label">Where</string>
<string name="when_label">When</string>
<string name="timezone_label">Time zone</string>
<string name="attendees_label">Guests</string>
<string name="today">Today</string>
<string name="tomorrow">Tomorrow</string>

You can declare your strings in res\values\strings.xml file like this.
<string-array name="vehiclescategory_array">
<item>Cars</item>
<item>Bikes</item>
<item>RVs</item>
<item>Trucks</item>
<item>Other Vehicles</item>
</string-array>
In your activity class, you can access them like the following.
String[] categories;
categories=getResources().getStringArray(R.array.vehiclescategory_array);
In the above list, whatever sequence you declare, the same way it is assigned to the array in your activity. Suppose Cars will be assigned to categories[0]. Hope this helps.

Field[] fields = R.string.class.getDeclaredFields(); // or Field[] fields = R.string.class.getFields();
String str = "";
for (int i =0; i < fields.length; i++) {
int resId = getResources().getIdentifier(fields[i].getName(), "string", getPackageName());
str += fields[i].getName() + " = ";
if (resId != 0) {
str += getResources().getString(resId);
}
str += "\n";
}
You will get all codes of strings with its values in "str" variable.

If you want to access all the Strings from the strings.xml file you could use reflection on the R.string class. An example can be found in this answer, you'll just need to replace drawables with strings.

You could declare an integer array with an entry for each string. I did this for an array of colors once, so I imagine it works for strings as well.
res/values/arrays.xml
<integer-array name="app_strings">
<item>#string/app_label</item>
<item>#string/what_label</item>
<item>#string/where_label</item>
<item>#string/when_label</item>
<item>#string/timezone_label</item>
<item>#string/attendees_label</item>
<item>#string/today</item>
<item>#string/tomorrow</item>
</integer-array>
Then in your code, you would loop over the array and use each value as the argument for getString().
int[] stringIds = getResources().getIntArray(R.array.app_strings);
String[] strings = new String[stringIds.length];
for (int i = 0; i < stringIds.length; i++) {
strings[i] = getString(stringIds[i]);
}
The problem is you have to manually update your arrays.xml whenever you modify your string resources, so it's certainly not ideal.

String[] categories = getResources().getStringArray(R.array.stars_array);
List<String> stringList = new ArrayList<>(Arrays.asList(categories));
use this simple one

Randomly select a string from strings.xml in Android

I need to randomly select a string defined within strings.xml file in android.
For example my strings.xml is :
<resources>
<string name="str1">Content comes here1</string>
<string name="str2">Content comes here2</string>
<string name="str3">Content comes here3</string>
</resources>
Can I randomly select one of these strings in my Activity?

Create an array contains all of your resource names you want to select:
String[] strs = new String[] {"str1", "str2", "str3"};
Get a random index:
int randomIndex = new Random().nextInt(3);
Get your random string from resource:
int resId = getResources().getIdentifier(strs[randomIndex ], "string", your_package_name);
String randomString = getString(resId);

The best way is you declare you Strings as an Array, then get it like this:
String[] arrayOfStrings = context.getResources().getStringArray(R.array.your_string_array);
String randomString = arrayOfStrings[new Random().nextInt(arrayOfStrings.length)];
Then you can use it as you like.

You would probable rather make it an array of strings (and then that is easier to select at random one of the array). Else, you can put the ids of your strings in an array and randomly select one of the items in the array.

How to concatenate strings and integer into a variable

It is a real silly questions but I can't get it to work. I've used the search option, but couldn't not find my answer for android.
What I would like to do it the following:
In res/strings.xml i've got several strings
<string name="good0">blablabla</string>
<string name="good1">balablabla2</string>
etc
I want to show those strings randomly in a those when something happens:
Toast.makeText(this,R.string.good+(Math.random()*10), Toast.LENGTH_LONG).show();
But this doesn't work.
Thanks a lot for your help!

Use a String Array.
In strings.xml:
<resources>
<string-array name="messages">
<item>blablabla</item>
<item>blablabla</item>
</string-array>
</resources>
Then, in code you will have something like:
String[] messages = getResources().getStringArray(R.array.messages);
Random r = new Random();
String message = messages[r.nextInt(messages.length)];
Toast.makeText(this, message, Toast.LENGTH_LONG).show();

R.string.good is an int because it refers to a Resource. This int IDENTIFIES a string in an XML file. Android provides a getString() for its resource identifiers.
Android Docs on String Resources
You'll have to get the String out of the resource file this way, then concatenate as normal.

You can't do that.
You will have to use a switch block.
String myString;
switch(Math.random() * 10) {
case 0:
myString = getString(R.string.good1);
break;
}
Toast.makeText(this, myString, Toast.LENGTH_LONG).show();

If you have multiple string values or integer values and you to store it in a single string then String Builder is the best for this
type of operation, For Example you have a string array and you want to
store in a single string and then display this string then use this
method. it will work hundred percent and it is too much suitable for
this type of problems.**
String my_str=null;
StringBuilder bldr=new StringBuilder();
for(int j=0;j<5;j++)
bldr.append(phonearray[j]).append(",");
my_str=bldr.toString();
here in this case i am assigning phone array to a single string and
then i will display it etc...