how to retrieve text from alert popup window code example

Example: how to handle alerts

- 2 types of alerts.
        1- HTML Alert: Nothing special with this one. 
          You just locate as WebElement then click.
        2- JS Alert: We cannot locate this web element
           in the HTML code. 
        You have to handle it differently
        - We handle alerts using Alert class
         creating ALERT object and 
        - Alert alert = driver.switchTo().alert();
         There are 3 options :
        - alert.accept();
        - alert.dismiss();
        - alert.sendKeys();
        
        
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    - How many different types of JS alerts do we have?
        - 3 types of JS Alerts.
            - Information : You can only accept.
            - Confirmation: You can accept or decline.
            - Prompt    : You can accept, decline, and/or sendKeys.