app/src/main/java/me/jj97181818/ch08_multiactivity/MainActivity.java

@@ -17,6 +17,16 @@ public class MainActivity extends AppCompatActivity {
         tvPath = findViewById(R.id.tv_path1);
     }
 
+    private void run(Intent intent) {
+        tvPath.setText(intent.getCharSequenceExtra("path"));
+        if (tvPath.getText().equals("")) {
+            tvPath.setText("1");
+        }
+        else {
+            tvPath.setText(tvPath.getText() + " -> 1");
+        }
+    }
+
     public void goBack (View v) {
         finish();
     }

app/src/main/java/me/jj97181818/ch08_multiactivity/SecondActivity.java

@@ -17,6 +17,11 @@ public class SecondActivity extends AppCompatActivity {
         tvPath = findViewById(R.id.tv_path2);
     }
 
+    private void run(Intent intent) {
+        tvPath.setText(intent.getCharSequenceExtra("path"));
+        tvPath.setText(tvPath.getText() + " -> 2");
+    }
+
     public void goBack (View v) {
         finish();
     }

app/src/main/java/me/jj97181818/ch08_multiactivity/ThirdActivity.java

@@ -17,6 +17,11 @@ public class ThirdActivity extends AppCompatActivity {
         tvPath = findViewById(R.id.tv_path3);
     }
 
+    private void run(Intent intent) {
+        tvPath.setText(intent.getCharSequenceExtra("path"));
+        tvPath.setText(tvPath.getText() + " -> 3");
+    }
+
     public void goBack (View v) {
         finish();
     }