The function specified in the setInterval
method keeps on running in a loop,
unless we stop it.
We can do this with the help of the clearInterval method.
The setInterval method returns a number value
that can be used to identify the timer set by the method.
The clearInterval method takes only one parameter,
the identifier value returned by the setInterval call
that set the timer to be cancelled.
In the example given above,
the function displayGreeting is
not run because clearInterval
method cancels the timer started
by setInterval.