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In this lesson we're going to talk about the variables.

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Everybody is essentially a container for a value.

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And since the name suggests it's a very wrong value that can be entered into that valuable variables

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are used to store different information and presented to us whenever we need them.

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But before we go that deep into understanding the role of variables in our programming language.

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Let's get a sense of some of the basic facts and then from there on we can one more advanced topics.

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So let me jump back into school and it makes for then I'm actually going to close this project and to

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start a new one.

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So file new project just like the last time I'm going to use.

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My question I'm going to use the command line tool.

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I'm going to call this long variable's project not in my variables project just like the last time I'm

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going to go to my dad and find him remove all the comments so that the code is a little bit easier to

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see and then get rid of this part of it.

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I like my presentation.

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I'm going to talk about four types of variables.

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Integers floats characters and what happens.

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So let's see what all these things so well we'll write that integers floats booleans and of course characters

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or characters.

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So let's see what they are.

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The first one is let's call it in and I'm going to call it my ends.

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Equals three for instance.

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Then I will write another one.

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And when I say floats and this one is going to be my float and that's going to be to point three and

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then I have another one card for my boolean and that is currently true.

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And then I have a cat there.

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Or my cat is the leader I see.

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So by just looking at them you can kind of get a sense of what they are.

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Integers are the whole numbers so whole numbers between if I can get the sign of infinity in

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infinity Yes I won.

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So between negative infinity and positive infinity and then float values are numbers with decimals.

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So such as three point three essentially any integer is also a float value as well.

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So this is essentially three point zero you could have twenty point zero in here.

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Boolean values are true or false or yes or no.

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So a sort of true I could use the yes I'm more used to using true because that makes more sense to me.

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And characters are essentially singular characters so integers all numbers float values that they have

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a decimal point to then put the means that they are either false or true characters which are the singular

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characters that meet just for this a little bit better.

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Now examples of these are such as these an integer value might be the number of the students number

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of the students in a class that number is a whole number.

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Numbers cannot be 2.8.

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That is either three or these two or anything like that.

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Flawed values are numbers such as let's say the distance between two houses two point three five kilometers

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or Miles if you're using a different system an imperial system.

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True or False systems are true or false variables are for situations where something is either happening

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or not happening.

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For instance your game might be paused or not.

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Is either of these two is either true or it is false.

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And finally there is a single type like the beginning there a game mean either of you or of your name.

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For in my case it would be of any use since your characters.

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So now that we have these then actually in all of these comments I can show you how we would end up

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printing these values.

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Let's get rid of that and I'm going to review that as we go along.

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I don't need one.

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I should have mentioned that some point died Objective-C is a white space ignoring programming language.

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It means whether you have these many lines between them or you don't.

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It doesn't make any difference.

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Also if you have two sets of code in the same same line as long as there is a semicolon between them

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and again it doesn't matter.

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Of course it's a good practice to give each of our declarations and each nine or four code its own line

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so it becomes a little easier to read them.

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And that's a very common practice that almost everyone uses.

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So I'm going to get that as well and I'm going to get it off.

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So the next important thing is about hope to the prison.

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This is essentially how could you print them.

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Obviously we can use a slug.

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This be the same format that we can go ahead of say and Aslaug.

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And that's actually good you know a challenge for you guys if you're new to programming.

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What happens if I say and it's like my let's run the

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let's wait for application to build and run on we can see the result.

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So the moment it builds on long it says hello world which is that line and then it says my eans because

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it's like preens everything finds between the two quotations identically whatever it finds.

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It prints them in here.

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So we somehow have to find a way to convert these values into a text value that can be printed in here.

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So to do that I'm going to say my intent or integer value is and then I'm going to say Give me a percent

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sign and then I.

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This means I'm formatting the code so that an integer is coming up.

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So it is going to write this part exactly as it is and then it's going to look for an integer.

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When I say calm or might it's not.

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This format might seem a little bit odd but this is the only format you have to get use to value types.

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Value value types value as many times as you want and you can have more of deeper ones of these.

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Print this out and then I'm going explain a little bit more.

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So now it says integer value is a.

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So it prints this part exactly as it is.

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So what ever I had in here let's say I had some random text in Yanar and then a column and then a space.

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All of that gets printed.

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And then the value gets printed so it says I had some random text in year and then divide you what if

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you don't want to have anything you can just drop that by its entirety and say just convert whatever

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is coming up which it prints 3.

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But it's kind of difficult to read it like this.

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That's why I use something like integer is a space.

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Why not let's go ahead and write this for a float value.

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So it becomes a lot easier.

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And then in here is percentage f and I'm going to say my float.

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Now now you should have kind of gotten a sense of.

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So there is a variable in here and that variable is containing a certain value and I'm using that variable

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in here.

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So instead of typing three point three Yeah I'm typing the name of the variable that holds on to that

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value.

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And if you print this now you will get to see where integer is three float is three point three.

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Like I said you can have multiple entries into one single slot.

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So I would essentially go ahead and say I saw an end here I would say the end is percentage this space

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and float is Karlo percentage as close quotations.

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And now it's expecting two values to show up.

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So I'm going to say come on my integer.

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So that's the first one for the integer and then this is the second one for float.

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So see two entries and two formatting essentially on two variables that correspond to these two types.

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If I print that now if it.

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Oh I forgot the semicolon at the end of here of course.

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So if he been down right now it says in these 3 and throw is something else you might get.

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You will get two warnings in here and you had more of those saying on use than ever.

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Because this variable has been declared but has never been used anywhere.

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And just one important definition that they should talk about declaration and definition and use rates.

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Now this line it says declare an integer card and defining it to be three.

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And here it's being used.

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Let me do another one.

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I'm going to say in my other in one when I close the semicon.

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So this is called a declaration declaration.

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It's means there is an integer called my other end but it doesn't know what is the value in it.

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So I could come in here and say my other hand is five and this is what we call it definition.

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It says Well the guy that we know that exist it's got a value of five.

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So declared and defined.

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All you could do both of them in the same goal.

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This is a very common practice and we'll see more and more and more of this in the in the coming sense.

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So let me drop out.

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I actually don't need that in a slide at the very top either.

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So I only need these four lines integer float Paulian and kiter and so forth you managed to print two

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of them and once two of them together I'm also going two planes and Aslaug and I'm going to say my Or

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just a single card.

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Years is under this percentage see what I'm going to say my time.

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The moment I will run it.

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It says count their ears See.

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You could of course print the boolean value but that doesn't really make much sense when we use boolean

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values.

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We usually compare them to a state we say if this boolean is to do something or the other thing I'm

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going to write that.

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And it's like the board is.

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And those are going to be H.H. D.

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And don't worry about the very complicated for of it.

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I will explain it in a bit.

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And there's going to be my in value.

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If you printed it should say is 1.

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Is it true.

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Yes it should say pool is one to get a better understanding of all of these different format things.

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I have been through the link with this lesson which is essentially here is string for the specifications

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in Objective-C.

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I having at this link for you guys that explains what each of these values are and what do each of them

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actually actually mean.

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How do you convert from one to another.

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My suggestion is that you don't try to memorize this.

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Just keep this thing handy so whenever you need one you can just go in here and get a sense of what

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they do to combat this particular type.

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Let's say you have a double and you want it to convert it into a string or let's say you're hard on

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unsigned target with integer and you wanted to convert it or if you had a floating value like the one

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that we had right now.

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So on and so forth.

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All of them are somewhere in this link and you can have a look.

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I personally don't know more than a few of these.

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Whenever I need the more advanced the odds are just coming here I will look for the one I need.

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I use it from here.

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So with that in mind this is a basic introduction to different valuable types the very basic primitive

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variable types.

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Let's move on to our next lesson.