MainActivity.java

package com.techpakka.sharedpreferences;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    Button btn_save,btn_load,btn_second;
    EditText ed_name,ed_email;
    TextView txt_name,txt_email;
    String str_name,str_email;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

         //initialising layout components
        btn_save = findViewById(R.id.btn_save);
        btn_load = findViewById(R.id.btn_load);
        btn_second = findViewById(R.id.btn_second);
        txt_name= findViewById(R.id.txt_name);
        txt_email= findViewById(R.id.txt_email); 
        ed_name = findViewById(R.id.ed1); 
        ed_email = findViewById(R.id.ed2);

    }
}