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was gonna guys? This is Bucky. And welcome to your 26th C++ tutorial.
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in this tutorial, I'm gonna be talking to guys about something called logical
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operators. now let me go ahead and build a simple program right now.
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say we're the owner of a nightclub and we wanted to calculate whether a person
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was allowed in
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or whether they weren't. so the first we looked at their age
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and we're going to make sure it's you know over 21
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because we gonna get sued. And next they thing were going to be looking at is how much
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money they have because
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we don't want to allow poor people into our, you know,
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five-star nightclub, so let's say they need more than
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five hundred dollars. so let's go ahead make this like person
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has six hundred fifty dollars. so we can test this
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like this if age is greater than 21.
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and if money
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is greater than what I say, 500? uhm,
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whu what did I just hit? insert, where the heck is my insert key on this keyboard?
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this keyboard is really messed up. now I look about it.
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so took me like five minutes a find the answer. It is actually by my, uh,
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up and down arrows. that's weird. so anyways,
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now that we had our nice little break, we go ahead write something like cout
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uhm, you are allowed
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in and make sure you sell it within nine and you
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and makes you so in I honor. or else this program just won't work.
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so let's go ahead and run this. and see what we get. We are allowed in because
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we indeed are greater than 21 and we have more than five hundred dollars
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So, you are saying alright. pretty cool program. Maybe open up a night club now
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but check this out, this can get kind of confusing after a while because
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this brace goes to this and this goes to this. were pretty
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easily distinguishable but what if we had five different tests that we need to
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check what if we had twenty different tests?
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well one little mistake say we had this over here
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Our program is still going to run fine but looks like this goes to this
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and this goes to main or something. who knows where this one goes.
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I mean putting a bunch if statements inside other if statements
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is not always the best idea. so we have a better way
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to test two or more things. and thats through the use of something called logical operators.
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and this allows you to make all your test on a single line.
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so here's what we can do in this case. go ahead and make your if statement and then
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my as well
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make our cout right now. Like you are
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allowed and explanation point, with end line (ENDL)
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and our if statement. go ahead and write your two tests like
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what did you put? age is greater than 21 and whenever you join them, 
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you use this logic ooperator "and
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and" and now go ahead and write money
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is greater than 500. now let's go ahead and run this and
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check it out. same results, a whole lot less programming.
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so what and and means, do this test
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and do this test. if they're both
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true then run this bit of code. And since they both were true
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it ran this bit of code if one of them was false, say we only had, you know,
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four dollars, like that, well yeah, this test is going to be true because we're greater
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than twenty one
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but this is going to be false, because four dollars is not greater than 500.
####
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And whenever you run it we are not allowed in check it out
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and also if both tests are false like
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where only two and hopes or on space repair
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say we're only two years old and we only have four dollars probably from tooth
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fairy
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of course we are not can be allowed in the club not cool but you know
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were two year old who needs to go clubbin when they're too anyways so
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basically a double and sign
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means this test all these test and if they're both true
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then you can run this bit of code by if one bomb is false
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or both from this false then we don't run it support of our
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and I say and with this test in this test
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but you can also have and in another test
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and even a man in another test and it's just gonna run all love your test
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and make sure that they're all true so the only way this bit of coz gonna run
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is a all your test in this is true
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so over San re: I i understand that logic operator
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all the tests need to be true in order to run but what if you say this
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re: I am I you know not to most
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fashion on my club owner so I'm gonna allow the man
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if on the wannabes test is true if there are over 21
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near loud and of course or if they have over five hundred dollars
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I'm in a while allow men because you know fr 20-year-old walks and was like
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a grand I know he's not 21 but I think we should let men anyways
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so say we want to do that make sure only one of the test room
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what we do is use a logical operator called the or
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logical cooperator and thats if you see above the Enter key on your keyboard
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in or shift you get these two little things I column pipe spa
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I think some peeps comp I points teachers I don't know what they're
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called
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on it's like a straight line up and down as you can see
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but settled ruler that's what it is and
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to affirm in a row is to or large cooperator
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in with the or large cooperator says is this
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on like that and where this one and this one had to be true
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only one of them has to be true in the other one can be false
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and it still runs to the disco so check this out we pass this test is true
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26 is greater than 21 but we don't have more than five hundred dollars so this
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is gonna be false 0 true
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and false so we run it and allows ascend even know
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want these was false but if both these were false
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see we're only six years old
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it wouldn't allow sinn so anyways what you have to remember that
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exist that and logical operator both the test have to be true
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with or watch cooperator wanted it s have to be true
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and another thing if both the tests are true in or
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its gonna run your bit of code so that say you were you know 64
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and you had you know a crap load of money it would Arron
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in even though they're both true it would allow UN anyway so
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with or this one or this one
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or both won't have to be true and with hand
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this one and this one has to be true and of course you can add another or
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test and another or test
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in another or test in when you're in program like this
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is gonna run through all your test and as long as one woman's true for example
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this one could be true
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and all these other ones could be false you know still runs bit code
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in or basically means look for at least one that's true
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and if it's true run that code so now that I repeated that
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about a hundred times you guys should understand difference between
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and in or logical operator and when you do what one use one
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versus the other I guess it depends on what can I call burning you want to be
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but for now that saw the car bomb can do something else right in the store
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arm done or uncovering next oral but if you click on an x-linked
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you can see something cash watchin and I'll see you then