These are the Following methods in Selenium are used in conditional and looping operations:-

1. isEnabled() method is used when you want to verify weather a certain element is enabled or not before executing a command.

    WebElement txtbox-username = driver.findElement(By.id("username"));
    if(txtbox-username.isEnabled()){
     txtbox-username.sendkeys("example");
   }
   

2.isDisplayed() method is used when you want to verify weather a certain element is displayed or not before executing a command.

     do{
            //do something here
    }while (driver.findElement(By.id("username")).isDisplayed() );

3.isSelected() method is used when you want to verity a certain checkbox,radio button or option in a drop- down box is selected.It doesnot work on other elements:-

   //"one-way" and "two-way" are radio buttons
   if(driver.findElement(By.id("one-way")).isSelected();
   {
    driver.findElement(By.id("two-way")).click();
   }