I have a question about Shread Preferences.

// Get value
public Boolean checkPreferences(String key){
    return pref.contains(key);
}


// Load Value
public String getPreferences(String key){
    return pref.getString(key, "");
}

// Save Value
public void savePreferences(String key, String value){
    SharedPreferences.Editor editor = pref.edit();
    editor.putString(key,value);

    editor.commit();
}

// Delete Key Data
public void removePreferences(String key){
    SharedPreferences.Editor editor = pref.edit();
    editor.remove(key);
    editor.commit();
}

// To delete a value (ALL Data
public void removeAllPreferences(){
    SharedPreferences.Editor editor = pref.edit();
    editor.clear();
    editor.commit();
}