Feature 1

app/src/main/java/edu/temple/helloworld/MainActivity.kt

@@ -10,17 +10,23 @@ class MainActivity : AppCompatActivity() {
 
     // Declare view properties - the first one is done for you
     lateinit var displayTextView: TextView
+    lateinit var nameEditText: EditText
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
         // Initialize with views defined in Layout - the first one is done for you
         displayTextView = findViewById(R.id.displayTextView)
-
+        nameEditText = findViewById(R.id.nameEditText)
 
         findViewById<Button>(R.id.clickMeButton).setOnClickListener {
-            displayTextView.text = "Hello, ${findViewById<EditText>(R.id.nameEditText).text}"
+            if(nameEditText.text.isEmpty()){
+                displayTextView.text = "Hello, World!"
+                nameEditText.error = "Please enter your name"
+                return@setOnClickListener
+            }
+            displayTextView.text = "Hello, ${nameEditText.text}"
         }