Java Programming Tutorial - 26 - Random Number Generator Video Lecture

what's going on everyone welcome to your
26th java tutorial and in this tutorial
i'm going to be building a random number
generator we're going to be importing
that from a class and i'm going to be
showing you how can use random number
generators to you guess that generate
random numbers so let's go ahead and
pretend we were building a program so we
could roll a dice and whatever the
outcome of dice it just outputted on our
screen so whenever we want to use random
numbers we need to import something like
we did scanner but this one is called a
random so go ahead put import java.util
in the name for this is random well a
smoker's cough or something so let's go
ahead and import random and now just
like the scanner we need to make an
object for it so I'm going to name my
dice you can name yours whatever you
want and of course that's equal to nu
naught R atom random with empty
parameters so now that we got our dice
object we can use random numbers so the
other thing we need is a temporary
variable called number it doesn't need
to be called number but I'm going to
call it number and this is going to
store the number that outputs on the
dice so for example it's going to store
1 2 6 depending on what number you roll
so I just don't want to roll the dice
once I want to roll it 10 times so for
that I'm going to need a for loop so
let's go ahead and put forward in
counter let's start it at 1 let's say
well counter is less than or equal to 10
less than or equal to 10 and let's
increment it by 1 so now we have a loop
that's executing 10 times so now we got
to give some instruction well since the
number doesn't have a value yet let's go
ahead and give it a value now what you
would usually do is use your object like
this number equals dice and then put
your dot separator next in because
you're getting an integer and then type
in how many options you want it to have
and since a dice has options 1 to 6 I'm
going to go
and +6 right there now this would work
right here and let me show you guys what
this does let's just go ahead and
system.out.print line and this is a
going to work fine so you can pay
attention to this number plus and we
don't need that other one right there so
look good
let's go enough let's run it and see
what it does it says 3 2 3 4 5 0 1 1 2 1
those look like a random numbers but the
problem is all of these random numbers
if you couldn't tell they go from 0 to 5
and why is that well I'm about to show
you guys right now whenever you use the
sarandon number generator and you give
it 6 options the options that it takes
by default are 0 through 5 if you use 6
again that's 6 numbers but when it
includes 0 it only goes 0 1 2 3 4 5 so
what if instead of 0 through 5 is your 6
options you wanted 1 through 6 which we
do want since it's the dice and the dice
doesn't have 0 well what will you do in
this case is simply put 1 plus and then
use our dice object to call this and
what this does is it still uses the
number 0 through 5 in this but adds 1 to
them so what it does is give the
illusion that we're getting the numbers
1 to 6 1 through 6 excuse me so now
let's run this again and we'll see what
we get as you can see there's no zeroes
and you get 4 1 6 2 2 4 3 1 1 2 and all
of these numbers are in the range of 1
to 6 and that's what we want so again if
you want to do this all you have to do
is list however many numbers you want in
your range and if you put 6 by default
it's going to give you 0 through 5 since
all computer counting starts at 0 but if
we want the numbers 1 to 6 we have to
add this little 1 addition sign and that
takes 0 through 5 and adds 1 to them or
increments um
or pushes them all over by one so
instead of 0 through 5 you get 1 to 6 so
that's your quick tutorial on how to
import on the random class how to make a
random object called dice and how to use
that dice object tag to a go fetch
random numbers for you and also how to
add one to give yourself kind of a
starting point so that's how in slot
machines or any program that uses random
numbers that they make that and we'll be
doing some more complex things with this
but for now I just wanted to give you
guys the core basics of a random number
generator and that's this so thank you
guys for watching copy this code and
play around with it and soon enough
there will be experts at it I promise
so again thank you guys for watching
don't forget to subscribe to my channel
and I'll see you next tutorial