Answers for "how to add alert message in javascript"

simple alert program in javascript

alert("this is the alert")

javascript alert

alert("string");

How do you handle js alerts?

If the alert on the browser comes from JavaScript, we use to
handle them Alert class.
Alert alert = driver.switchTo.alert();
alert.accept();
alert.dismiss();
alert.sendKeys();
alert.getText();

java script alert

alert("This is an alert !");