Skip to main content

Simple calculator program in android

Hi everyone.Here I am going to put a simple calculator program in Android.

Please find the required files
1.MainActivity.java
2. activity_main.xml (Layoutfile)
3. String.xml

1. MainActivity.java

/* MainActivity starts here */
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

/* Variable declaration starts here */
Button plusButton ;
     Button minusButton;
Button mulButton ;
Button divideButton;
EditText number1EditText ;
EditText number2EditText;
TextView result; 
 
/* End of variable declaration*/

/*Please don't give any code inside these two function */
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
variable_defenition();
call_to_main_function();

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

/* End of function */

public void variable_defenition(){
/* Variable declaration starts here */

plusButton = (Button) findViewById(R.id.plusbutton);
minusButton = (Button) findViewById(R.id.minusbutton);
mulButton = (Button) findViewById(R.id.multiplybutton);
divideButton = (Button) findViewById(R.id.dividebutton);
number1EditText = (EditText) findViewById(R.id.edittextnumber1);
number2EditText = (EditText) findViewById(R.id.edittextnumber2);
result = (TextView) findViewById(R.id.textResult); 
 
/* End of variable declaration*/
}

public void call_to_main_function(){

/*Code for Addition */

plusButton.setOnClickListener(new View.OnClickListener() {
          public void onClick(View v) {
          String str1 = number1EditText.getText().toString();   
          String str2 = number2EditText.getText().toString(); 
          Float num1=Float.parseFloat(str1);
          Float num2=Float.parseFloat(str2);
          Float interresult;
          
          interresult = num1 + num2;
          result.setText(interresult.toString());
          } });

/* Code for addition ends here*/


/*Code for Subtraction */
minusButton.setOnClickListener(new View.OnClickListener() {
          public void onClick(View v) {
          String str1 = number1EditText.getText().toString();   
          String str2 = number2EditText.getText().toString(); 
          Float num1=Float.parseFloat(str1);
          Float num2=Float.parseFloat(str2);
                   Float interresult;
          
          interresult = num1 - num2;
          result.setText(interresult.toString() );
          
          
          } });

/* Code for Subtraction ends here*/

/*Code for Multiplication */
mulButton.setOnClickListener(new View.OnClickListener() {
          public void onClick(View v) {
          String str1 = number1EditText.getText().toString();   
          String str2 = number2EditText.getText().toString(); 
          Float num1=Float.parseFloat(str1);
          Float num2=Float.parseFloat(str2);
                   Float interresult;
          
          interresult = num1 * num2;
          result.setText(interresult.toString());
          
          
          } });

/* Code for Multiplication ends here*/


/*Code for Division */
divideButton.setOnClickListener(new View.OnClickListener() {
          public void onClick(View v) {
          String str1 = number1EditText.getText().toString();   
          String str2 = number2EditText.getText().toString(); 
          Float num1=Float.parseFloat(str1);
          Float num2=Float.parseFloat(str2);
                   Float interresult;
          
                   if(num2 == 0)
                  result.setText("Cannot divide by 0");
                   else {
                   interresult = num1 / num2;
          result.setText(interresult.toString());
                   }
          
          
          } });

/* Code for Division ends here*/

}//End of call_to_main_function

}

/* MainActivity ends here */


2. activity_main.xml
<!-- Layout starts here-->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   
    <LinearLayout
   android:layout_width="fill_parent"
   android:layout_height="wrap_content"
   android:orientation="vertical" >  
    
    <TextView android:id="@+id/textNumber1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/enumber1" />
    <EditText
        android:id="@+id/edittextnumber1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:text="@string/number1" android:inputType="number" />
    
    
     <TextView android:id="@+id/textNumber2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/enumber2" />
      <EditText
        android:id="@+id/edittextnumber2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:text="@string/number2" android:inputType="number" />
    
     
     </LinearLayout>
     
    <LinearLayout 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
   android:orientation="horizontal" >   
   
  <Button
    android:id="@+id/plusbutton"    
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/plus"
    android:onClick="sendMessage" />
  <Button
       android:id="@+id/minusbutton"  
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/minus"
    android:onClick="sendMessage" />
    
    <Button
      android:id="@+id/multiplybutton"    
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     android:text="@string/multiply"
    android:onClick="sendMessage" />
    
     <Button
      android:id="@+id/dividebutton" 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/divide"
    android:onClick="sendMessage" />
    

</LinearLayout >
    
     
<LinearLayout 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
   android:orientation="vertical" >   
   
 <TextView android:id="@+id/textResultLabel"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/calcResult"
       />


  <TextView android:id="@+id/textResult"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="" />

</LinearLayout >


<!-- End of Linear layout -->

</LinearLayout>


<!-- Layout ends here-->

3. String.xml


<!-- Strings starts here-->
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Calculator</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>
    <string name="calcResult">Result </string>
    <string name="number1"></string>
    <string name="number2"></string>
    <string name="plus">+</string>
<string name="minus">-</string>
<string name="multiply">*</string>
<string name="divide">/</string>
<string name="enumber1">Enter Number 1 </string>
    <string name="enumber2">Enter Number 2 </string>
</resources>
<!-- Strings end here-->

Comments

Popular posts from this blog

UNIX : How to ignore lines with certain names

Sometimes we need to ignore multiple lines with certain words and get the list out of the file. usually it will be a log file to read . The below grep command can be used to ignore multiple words present in a text file. Lets say the file contain $ cat list.txt apple orange apple banana papaya Now we need to ignore line with orange , banana and papaya . So we can use the below grep command. $ cat list.txt | grep -Ev "orange|banana|papaya" apple apple It will ignore lines with the words in -v part of grep.

UNIX : How to get record count from zipped file

Sometimes we may need to get records count from file . For that we can use wc -l , command with file name. In some situation the file will be in compressed format . wc -l will not directly work with zipped files . In this case we can do zcat the file and pipe the word count command with it. Example : Let say we have a file cricketData.dat.gz To get word count from the file use : zcat cricketData.dat.gz | wc -l This will give the record count.

Python : How to create your own module in python

Python modules are easy to create and imported in to your python program. How to create a module? The python program itself can be called as a python module. All the function which you find that can be grouped together can be put into the file. Here a simple example to print the text on display is used and called as techinfotalks. #!/usr/bin/python # Python Module def func_hi(): print "Welcome to the module" #End How to use the module in program? You just import the module created by calling the import.After that directly call the function which ever you need.The module named techinfotalks is imported as named as ti. #!/usr/bin/python import techinfotalks as ti print "Calling funcion in module" ti.func_hi() #End of program