In this tutorial how to perform simple arithmetic operations in Android is shown.<\/p>\n
Code:<\/p>\n
activity_main.xml<\/p>\n
<RelativeLayout xmlns:android=”http:\/\/schemas.android.com\/apk\/res\/android”
\nxmlns:tools=”http:\/\/schemas.android.com\/tools”
\nandroid:layout_width=”match_parent”
\nandroid:layout_height=”match_parent”
\nandroid:paddingBottom=”@dimen\/activity_vertical_margin”
\nandroid:paddingLeft=”@dimen\/activity_horizontal_margin”
\nandroid:paddingRight=”@dimen\/activity_horizontal_margin”
\nandroid:paddingTop=”@dimen\/activity_vertical_margin”
\ntools:context=”.MainActivity” ><\/p>\n
<EditText
\nandroid:id=”@+id\/no1″
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignParentTop=”true”
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”44dp”
\nandroid:ems=”10″
\nandroid:hint=”Please enter a number” ><\/p>\n
<requestFocus \/>
\n<\/EditText><\/p>\n
<EditText
\nandroid:id=”@+id\/no2″
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_below=”@+id\/no1″
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”31dp”
\nandroid:ems=”10″
\nandroid:hint=”Please enter a number” \/><\/p>\n
<Button
\nandroid:id=”@+id\/add”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignParentLeft=”true”
\nandroid:layout_centerVertical=”true”
\nandroid:layout_marginLeft=”16dp”
\nandroid:onClick=”onAdd”
\nandroid:text=”+” \/><\/p>\n
<Button
\nandroid:id=”@+id\/sub”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_centerVertical=”true”
\nandroid:layout_toRightOf=”@+id\/add”
\nandroid:onClick=”onSub”
\nandroid:text=”-” \/><\/p>\n
<TextView
\nandroid:id=”@+id\/ans”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignParentBottom=”true”
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginBottom=”65dp”
\nandroid:text=”TextView” \/><\/p>\n
<Button
\nandroid:id=”@+id\/div”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_centerVertical=”true”
\nandroid:layout_toLeftOf=”@+id\/mul”
\nandroid:onClick=”onDiv”
\nandroid:text=”\/” \/><\/p>\n
<Button
\nandroid:id=”@+id\/mul”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_alignParentRight=”true”
\nandroid:layout_centerVertical=”true”
\nandroid:layout_marginRight=”21dp”
\nandroid:onClick=”onMul”
\nandroid:text=”*” \/><\/p>\n
<Button
\nandroid:id=”@+id\/reset”
\nandroid:layout_width=”wrap_content”
\nandroid:layout_height=”wrap_content”
\nandroid:layout_below=”@+id\/sub”
\nandroid:layout_centerHorizontal=”true”
\nandroid:layout_marginTop=”30dp”
\nandroid:onClick=”onReset”
\nandroid:text=”Reset” \/><\/p>\n
<\/RelativeLayout><\/p>\n
MainActivity.java<\/p>\n
package com.example.demo;<\/p>\n
import android.os.Bundle;
\nimport android.app.Activity;
\nimport android.view.Menu;
\nimport android.view.View;
\nimport android.widget.EditText;
\nimport android.widget.TextView;
\npublic class MainActivity extends Activity {<\/p>\n
EditText no1,no2;
\nTextView ans;
\nint n1,n2,a;<\/p>\n
@Override
\nprotected void onCreate(Bundle savedInstanceState) {
\nsuper.onCreate(savedInstanceState);
\nsetContentView(R.layout.activity_main);
\nno1=(EditText)findViewById(R.id.no1);
\nno2=(EditText)findViewById(R.id.no2);
\nans=(TextView)findViewById(R.id.ans);
\n}<\/p>\n
public void onAdd(View v)
\n{
\nn1=Integer.parseInt(no1.getText().toString());
\nn2=Integer.parseInt(no2.getText().toString());
\na=n1+n2;
\nans.setText(toString().valueOf(a));
\n}<\/p>\n
public void onSub(View v)
\n{
\nn1=Integer.parseInt(no1.getText().toString());
\nn2=Integer.parseInt(no2.getText().toString());
\na=n1-n2;
\nans.setText(toString().valueOf(a));
\n}<\/p>\n
public void onDiv(View v)
\n{
\nn1=Integer.parseInt(no1.getText().toString());
\nn2=Integer.parseInt(no2.getText().toString());
\na=n1\/n2;
\nans.setText(toString().valueOf(a));
\n}<\/p>\n
public void onMul(View v)
\n{
\nn1=Integer.parseInt(no1.getText().toString());
\nn2=Integer.parseInt(no2.getText().toString());
\na=n1*n2;
\nans.setText(toString().valueOf(a));
\n}<\/p>\n
public void onReset(View v)
\n{
\nans.setText(” “);
\nno1.setText(” “);
\nno2.setText(” “);
\n}<\/p>\n
@Override
\npublic boolean onCreateOptionsMenu(Menu menu) {
\n\/\/ Inflate the menu; this adds items to the action bar if it is present.
\ngetMenuInflater().inflate(R.menu.main, menu);
\nreturn true;
\n}<\/p>\n
}<\/p>\n
<\/p>\n