Android: SharedPreferences Boolean

Question

does someone know where the mistake is? There is an error in Android Studio.

The following is the code for now.

final String keyFirstTime = "keyFirstTime";

prefsEditor.putBoolean(keyFirstTime, false);

if (keyFirstTime = false) {

Thanks in advance.

Well, `keyFirstTime` is a `String`, so you can't assign a boolean value to it. And the expression in an `if` statement needs to be of `boolean` (or `Boolean`) type too. — Andy Turner, Jan 18 '17 at 16:36
@BalkrishnaRawool nope, that's still a compiler error, because strings are never identical to booleans. — Andy Turner, Jan 18 '17 at 16:39
@BalkrishnaRawool and I'm saying that your suggestion is incorrect: it's just replacing one compiler error with another. — Andy Turner, Jan 18 '17 at 16:41
there is an error for **prefs.getBoolean(keyFirstTime) = false** too — quidproquo, Jan 18 '17 at 16:42
Your code doesn't contain `prefs.getBoolean(keyFirstTime) = false`. But that would be an error because you can only assign to a variable; method results aren't variables. — Andy Turner, Jan 18 '17 at 16:46

score 2 · Answer 1 · edited May 23 '17 at 11:45

keyFirstTime is a string (see comment)
you are PUTTING a value not getting a value
You are using an assignment in an if statement
You are comparing a STRING to a BOOLEAN

In Activity 1 you should have:

final String keyFirstTime = "keyFirstTime";
prefsEditor.putBoolean(keyFirstTime, false);

In Activity 2 you should have:

boolean firstTime = prefs.getBoolean(keyFirstTime, false); //you don't need the editor
if (firstTime) {
    ...
}

Please go here for a tutorial: https://developer.android.com/training/basics/data-storage/shared-preferences.html

EDIT Try doing this (stolen from here)

private static final String FIRST_RUN = "FIRST_RUN";
SharedPreferences prefs = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...

    prefs = getSharedPreferences(getApplicationContext().getPackageName(), MODE_PRIVATE);
}

@Override
protected void onResume() {
    super.onResume();

    if (prefs.getBoolean(FIRST_RUN, true)) {           
        prefs.edit().putBoolean(FIRST_RUN, false).commit();
        //call relevant function for first run
    } else {
        //call relevant function for every other run
    }
}

thank you, but what if I want that keyFirstTime is true at the beginning (the first time that the user started the app) and change the value from true to false (if a button is clicked) — quidproquo, Jan 18 '17 at 16:45
You can change the value at any point as long as you use the same string as the key in the SharedPreferences — Quintin Balsdon, Jan 18 '17 at 16:45
You should mark this as the answer if it answers your question please — Quintin Balsdon, Jan 18 '17 at 18:13

score -1 · Answer 2 · answered Jan 18 '17 at 17:03

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences();  prefs.edit().putBoolean("keyFirstTime", true).commit();

Now to get Boolean value you have to use

Boolean check = prefs.getBoolean("keyFirstTime", false);

Now you can check this way

if(check){ your code here }

Android: SharedPreferences Boolean

2 Answers2