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Android | App to Add Two Numbers
Below are the steps for Creating a Simple Android Application to Add Two Numbers
- STEP-1: First of all go to the xml file
- STEP-2: Now go to the text and write the code for adding 3 textview,2 textedit and Button and Assign ID to each component. Assign margin top, left, right for the location.
- STEP-3: Now, open up the activity java file.
- STEP-4: Declare few variables and the values entered in the Text Views can be read by using an id which we have set in the XML code above.
- STEP-5: Add the click listener to the Add button.
- STEP-6: When the Add button has been clicked, add the values and store it into the sum variable.
- STEP-7: To show the output in the result text view, set the sum in the textview.
Complete code of layout xml file and java file is given below.
activity_main.xml
<!--The activity_main.xml is a layout file an XML-based layout is a file that defines the different widgets to be used in the UI and the relations between those widgets and their containers. --> <? xml version = "1.0" encoding = "utf-8" ?> android:layout_width = "match_parent" android:layout_height = "match_parent" tools:context = ".MainActivity" tools:layout_editor_absoluteY = "81dp" > <!-- Text view for result view--> < TextView android:id = "@+id/textView_answer" android:layout_width = "100dp" android:layout_height = "25dp" android:layout_marginLeft = "130dp" android:layout_marginTop = "300dp" android:text = "0" android:textSize = "20dp" android:textStyle = "bold" /> <!--take the input first number--> < EditText android:id = "@+id/editText_first_no" android:layout_width = "150dp" android:layout_height = "40dp" android:layout_marginLeft = "200dp" android:layout_marginTop = "40dp" android:inputType = "number" /> <!-- for message input first number--> < TextView android:id = "@+id/textView_first_no" android:layout_width = "150dp" android:layout_height = "25dp" android:layout_marginLeft = "10dp" android:layout_marginTop = "50dp" android:text = "First number" android:textSize = "20dp" /> <!--view message --> < TextView android:id = "@+id/textView_second_no" android:layout_width = "150dp" android:layout_height = "25dp" android:layout_marginLeft = "10dp" android:layout_marginTop = "100dp" android:text = "Second number" android:textSize = "20dp" /> <!-- take input for second number --> < EditText android:id = "@+id/editText_second_no" android:layout_width = "150dp" android:layout_height = "40dp" android:layout_marginLeft = "200dp" android:layout_marginTop = "90dp" android:inputType = "number" tools:ignore = "MissingConstraints" /> <!-- button for run add logic and view result --> < Button android:id = "@+id/add_button" android:layout_width = "100dp" android:layout_height = "50dp" android:layout_marginLeft = "110dp" android:layout_marginTop = "200dp" android:text = "ADD" /> </ RelativeLayout > |
MainActivity.java
// Each new activity has its own layout and Java files, // here we build the logic for adding two number package org.geeksforgeeks.addtwonumbers; 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 { // define the global variable // variable number1, number2 for input input number // Add_button, result textView EditText number1; EditText number2; Button Add_button; TextView result; int ans= 0 ; @Override protected void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.activity_main); // by ID we can use each component which id is assign in xml file number1=(EditText) findViewById(R.id.editText_first_no); number2=(EditText) findViewById(R.id.editText_second_no); Add_button=(Button) findViewById(R.id.add_button); result = (TextView) findViewById(R.id.textView_answer); // Add_button add clicklistener Add_button.setOnClickListener( new View.OnClickListener() { public void onClick(View v) { // num1 or num2 double type // get data which is in edittext, convert it to string // using parse Double convert it to Double type double num1 = Double.parseDouble(number1.getText().toString()); double num2 = Double.parseDouble(number2.getText().toString()); // add both number and store it to sum double sum = num1 + num2; // set it ot result textview result.setText(Double.toString(sum)); } }); } } |
After Complete layout xml file it will be shown as given below
Output:
Note: Similarly, Android App to subtract, multiply and divide numbers can be made by making minor changes in the Java and XML code.