//EXAMPLE

class MainActivity : AppCompatActivity() {  
  
    private val sharedPrefFile = "kotlinsharedpreference"  
  
    override fun onCreate(savedInstanceState: Bundle?) {  
        super.onCreate(savedInstanceState)  
        setContentView(R.layout.activity_main)  
  
        val inputId = findViewById<EditText>(R.id.editId)  
        val inputName = findViewById<EditText>(R.id.editName)  
        val outputId = findViewById<TextView>(R.id.textViewShowId)  
        val outputName = findViewById<TextView>(R.id.textViewShowName)  
  
        val btnSave = findViewById<Button>(R.id.save)  
        val btnView = findViewById<Button>(R.id.view)  
        val btnClear = findViewById<Button>(R.id.clear)  
        val sharedPreferences: SharedPreferences = this.getSharedPreferences(sharedPrefFile,Context.MODE_PRIVATE)  
        btnSave.setOnClickListener(View.OnClickListener {  
            val id:Int = Integer.parseInt(inputId.text.toString())  
            val name:String = inputName.text.toString()  
            val editor:SharedPreferences.Editor =  sharedPreferences.edit()  
            editor.putInt("id_key",id)  
            editor.putString("name_key",name)  
            editor.apply()  
            editor.commit()  
        })  
        btnView.setOnClickListener {  
            val sharedIdValue = sharedPreferences.getInt("id_key",0)  
            val sharedNameValue = sharedPreferences.getString("name_key","defaultname")  
            if(sharedIdValue.equals(0) && sharedNameValue.equals("defaultname")){  
                outputName.setText("default name: ${sharedNameValue}").toString()  
                outputId.setText("default id: ${sharedIdValue.toString()}")  
            }else{  
                outputName.setText(sharedNameValue).toString()  
                outputId.setText(sharedIdValue.toString())  
            }  
  
        }  
        btnClear.setOnClickListener(View.OnClickListener {  
            val editor = sharedPreferences.edit()  
            editor.clear()  
            editor.apply()  
            outputName.setText("").toString()  
            outputId.setText("".toString())  
        })  
    }  
}