Selenium multiple popup handling

How to handle popup in selenium?
In popup handling we switch on alert box by using switchTo() with alert() on driver object.
Example:-         Alert alert2 = driver.switchTo().alert();
and if you want to get alert text then use getText() on alert object.
 Example: -       String text2 =alert3.getText();


There are 3 type of alert in webpages.
1.simple alert.
2.confirmation alert
3.Text box alert

1.Simple alert box js code example:-
Here inbuilt alert method used for popup.
"function simpleAlert()
{
alert('ok')
}"

2.Confirmation alert js code example:-
Here inbuilt confirm method used.
"function confirmation(){
if (confirm(""Press a button!"")) {
  txt = ""You pressed OK!"";
} else {
  txt = ""You pressed Cancel!"";
}
}"

3.Text box alert js code example:- 
In this we use prompt method of windows.
"
function myFunction() {
  var txt;
  var person = prompt(""Please enter your website:"", ""www.onlinetutorial.info"");
  if (person == null || person == """") {
    txt = ""User cancelled the prompt."";
  } else {
    txt = ""Hello "" + person + ""! How are you today?"";
  }
  document.getElementById(""demo"").innerHTML = txt;
}"

Example of popup handling in selenium with complete java code:-

"package pkg1;

import org.openqa.selenium.Alert;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class MyClass913_popup_handling { 
    public static void main(String[] args) {       
   
        System.setProperty(""webdriver.chrome.driver"",""C:\\Users\\Desk-105\\Documents\\SELENIUM\\chromedriver.exe"");   
        WebDriver driver = new ChromeDriver();   

        driver.get("https://www.onlinetutorial.info/p/selenium-popup-handling.html");

        /**
         * simple alert
         */
        WebElement element = driver.findElement(By.id(""textbox_1""));
        element.sendKeys(""pradeep yadav"");
        WebElement element2 = driver.findElement(By.id(""button_submit""));
        element2.click();
        Alert alert = driver.switchTo().alert();
     
     
        try {
   Thread.sleep(5000);
  } catch (InterruptedException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
     
     
        alert.accept();
     
        /**
         * confirmation alert popup
         */
     
        WebElement element3 = driver.findElement(By.id(""button_submit2""));
        element3.click();
     
        Alert alert2 = driver.switchTo().alert();
        String text =alert2.getText();
        System.out.println(text);
     
        try {
        Thread.sleep(5000);
       } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
       }
           
        alert2.accept();
     
        /**
         * text box popup
         */
     
        WebElement element4 = driver.findElement(By.id(""button_submit3""));
        element4.click();
     
        Alert alert3 = driver.switchTo().alert();
        String text2 =alert3.getText();
        System.out.println(text2);
     
        try {
        Thread.sleep(5000);
       } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
       }
           
        alert3.accept();
     
     
     
     
//        driver.close();
    }
}
"