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what's going on guys? welcome back to your seventeenth c plus plus
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tutorial and in this tutorial i'm going to be covering something called the if
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else statement. now let's go ahead and first I want to build a basic if statement
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because an if/else statement is pretty much like an enhanced if statement. so let's go ahead
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and use the knowledge or to information that we learned in the last
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tutorial and build on it. so let's go ahead make a simple program.
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we have a variable called "age" and go ahead and set equal to whatever your age is
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now go ahead and make a basic if statement. Now if you remember from the
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last
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tutorial all an if statement does is it runs
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a simple test. If that test this true it runs a bit of code.
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if that test is false, it doesn't do anything. so let's go ahead and test
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age. say if age is greater than
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sixty let's go ahead and say, uhm,
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cout "Wow"
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you are old. so if the user is over sixty,
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let's go ahead and say, "you are old" and now
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let's go ahead and end that line. run this program and see what we get.
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we get nothing. and that is because I'm
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24, so this program does nothing. but you build this program
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you show it to your boss. you're like hey where's my raise? And they're like, wow,
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this program is impressive in all, however wouldn't it be nice
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if we could give a message to the user no matter how old they are.
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what if instead of skipping this if the test is false
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Let's give him an alternative message like
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if anyone's over 60 we're going to tell them they're old.
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if anyone is under 60 we're going to tell them, hey
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get a job. So, you are saying alright.
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I suppose I could put another if statement and then
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write age is less than 60. But you know what? that isn't the best way to do things
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I'm sure you guys something called if else statement. so the IF statement
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basically
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ran a simple test. and if that test is true it ran this bit of code
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And if it was false it did nothing. it skipped it
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but now we want to say, alright,
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else if the test is false then we want to run this bit of code
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so either way its going to run a bit of code
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either way. if it's true its gonna run this bit of code.
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Let me just go ahead copy that. if it false
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its gonna run this bit of code. but let's not put "wow, you are old" for either one.
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If they're under 60, let's go ahead and write
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"you are young, get a job"
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so now when we go ahead and run a program,
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unlike before when it says alright, since this test is a true I'm just going to
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skip it says alright,
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this test isn't true, so what am I supposed to do it's false?
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What is it I am supposed to do with else. so let's go ahead and
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enough of me talking. run  it and it says "you are young,
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get a job" and of course if the user is like
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87 we run the program and they say
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wow, you are old. so now you can see instead of just having a basic if
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statement
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where it was either run a bit code or do nothing
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we now have the option of something happens for true
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and something happens for false. so now either way
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your computer program is going to do something so that is the basics
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of an if/ else statement. So, now that you guys know that, 
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let me go even deeper. I said that you can
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go ahead and run a line of code inside an if statement.
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well you can also run multiple lines of code just by putting them
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under each other so if you go ahead and we copy this, we can go ahead and paste it
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paste it, paste it. that it doesn't matter you can go ahead and run it four times
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as long as it's in between those braces right there.
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So, you are saying alright. what if
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I wanted to do something like this. what if not only
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I wanted to check if they were over 60, but if they were over 60
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I wanna check they were over a hundred. so let's go ahead and
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do that. so what mmm, I want to teach you guys
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now is that, inside if statements
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instead of just running simple lines of code you can also put additional if
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statements.
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this is called nesting IF statements. so let's go ahead and say
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if and remember this code is only gonna run if the user is over sixty so now we
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want to test
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if the user is over 100.
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and then we're going to write cout
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uhm, "why are you still alive?"
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 I know this is harsh but hey
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just trying to get the point across. so now let's go ahead
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we'll run this bit of code right now. so our programs going to say this
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Alright, if the age is over 60
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which it is, I'm gonna run this bit of code right here,
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and in this bit of code, I'm gonna test if the user is over
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100. well they're not over 100, but they are over 60. so nothing is going to happen
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so we're going to run this nothing is going to happen. But, say
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our user was a 178. pretty old huh?
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well, we're gonna say alright, is your age over 60?
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yes, so now go here. is your ave (inaudable)
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is your age over 100? yes it is, so now
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run this bit of code right here. and we're goint to go ahead and run it and is going to
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say
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why are you still alive? because come on guys let's face it
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if you're 178 years old, you should be dead. just saying.
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so now we begin to see
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how we can make complex test and very complex programs. and,
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I know that I it's called nesting and "if" statement
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inside another if statement. but you can also
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nest and IF / else in here
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and you can also nest another if in here. And,
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we can do is you can nest if inside
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if inside if's as many times as you want.
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But, say you wanna test if the user is over 10 then over 20 then over 30 then over
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40 then 50. well, there's even a a more simple way
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to do this then nesting a thousand different ifs insdie each other
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and I probably teaching that in upcoming tutorials, but for now
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what I want you guys take away from this tutorial is instead of a basic
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if statement, where if to test is false
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then it just skips the code, you can now add in else
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and what this does is gives it an alternative choice
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and also aside from that, you can also nest
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if inside other ifs. So, that you can basically test two things.
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and if two things are true, run a bit code.
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So, as long as you understand those concepts, you should be good to go. So,
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for now thank you guys for watching. Don't forget to subscribe. And yeah,
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if you have any questions, send me a message on my website, the New Boston dot
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com
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and I'll be glad to answer for he said thank you for watching.
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Don't forget to sign up and I will see you next tutorial.