Java for Fucking Idiots: Learn the Basics of Java Programming Without any experience!

if
(letter ==
'F'
) {
continue
;
}
System.
out
.println(letter);
}
It might be a contrived example, but it’s a reminder that we need to be
careful inside loops that we don’t infinitely spin our wheels.
The doo doo while loop
Note that a loop doesn’t have to run at all. What if before we did the loop
on our alphabet, we set the index to a value other than 0? A value outside
the size of the alphabet?
int
index =
87
;
while
(index < alphabet.
length
) 
…
Well that’s simply too high! The while loop sees the index isn’t less than
26, so it doesn’t run even once! Not a single letter is printed out.
That’s good though, right? No problem with that. The 
while
statement is
simple and does what it’s supposed to: runs code over and over again while
a certain condition is true.

---

Here’s comes the fun, doo doo doo doo
However, at some point the Java developers thought: why don’t we fix this?
Oh, it makes sense as-is, but why don’t we add another kind of loop for no
reason?
(Note: this actual conversation didn’t happen)
That’s when we get the “do-while” loop, or “doo doo” while loop, as I call
it. Because it’s stupid and no one uses it, except the one guy reading this
that is infuriated that I’m insulting his favorite language construct.
Here’s how it works:
I write some code. It’s run once. Then, we start a while loop. It might be run
again.
do
{
System.
out
.println(
"I hate that I exist."
);
}
while
(
false
);
What do you think would happen if we run this code? Take a guess inside
your little noggin.
“I hate that I exist” is print out to the screen once. Then, the condition is
evaluated at the end .
Since I literally wrote false (the opposite of true ), the loop doesn’t keep
going. One could argue the loop never started. This is the opposite of the
while loop, which looks at the condition at the beginning .
I’ll give you some more: