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Hell who are they welcome to feed you on Javascript variables.

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Variables are containers that you can use to store values in.

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It's kind of like a little too eerie or memory holds value and that can be referenced later variable

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must have a name.

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And there are conditions in name in variables.

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For example you can not begin a variable name with any number you can't for example name it variable

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for cash.

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You can however name it cash 24.

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You can not use mathematical or logical operators in variable names.

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For example you can name a variable 7 star or 7 question mark consort.

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You can't use punctuation mark.

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However you can use an underscore to name variable names but that's the only exception.

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You can't use any other punch Nations.

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Jeb us group names must not contain spaces so you can have a variable name called Cash 24.

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And they can not be a space between the cash and the 24.

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So the names must contain no spaces variable names are case sensitive variable.

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The lower case X and upper case X are two different variables.

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You can not use any javascript key words or any key word that is part of the javascript language.

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You can't use that variable name for example you can't have a variable code alert something or prompt.

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Those are part of the javascript key word.

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The name on the variable itself is really up to us or to you.

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So more is better.

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The name you give is a variable represent the piece of data that you want to store.

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For example if you are storing details about customer accounts you can name the variable customer count

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so it makes it relevant or Shehan.

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If you are storing details about an address you can name the variable cost to address a variable I created

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using the key word var which is if you are in a lower case.

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I will be creating a sample variable in a few minutes.

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All right just before I create some variables.

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I just want to go through what I have spoken about so far.

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That variables are containers used to store values that can be referenced and used later.

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Variable names are case sensitive so you name it variable.

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Lower case X and try and change the value thinking it's an upper case X..

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You may get some issues.

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Variables are created or declared using the key word and here are.

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You can not begin the variable names with no.

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E.g. 247 carriage you can reverse it like cash two for seven dollars.

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Group names must not have spaces between them.

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If fast cars tell us groupy was cannot be used like learned some plant variable without value is known

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as undefined.

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Also why is you arguing the variable of value.

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You can change it any time.

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So let's go ahead and create some variables.

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All right this is my sample script here.

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This is my text said it all.

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This is the page that this code here displays.

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So got one content which is this one tack here.

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Right so this is the javascript so what I need to focus on is the code between the script tag.

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So I've created a few variables here.

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The first one is a variable to chord X and it stores the value of 27.

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Next one is a variable called Y is stores of value of 38.

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And they've got the variables Z and values equal still x plus y have also gone at a variable called

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my car when a variable name is set up like it's called.

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Come all k so you be in with lower case and then the first letter is an upper case.

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I've also gone at a variable first name variable here.

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Hasn't got any value.

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My car hasn't got any value but these ones got a value.

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It's always good to declare your variables at the beginning of the script and also set a value.

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If you know what your values are so if I remove this comment run this alert.

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It should give me the value of x and y some say an alert.

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The result of a z z.

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Means.

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Variable said.

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So if I say that and run that it should show me my browser.

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So click run in Firefox.

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So the last 6 to 5 so do result of Z is 65 to Z.

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It's a tool of x and y.

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So next if I run let me comment this again.

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If I run this piece of code here you see what it says go run.

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It says on defying new reason it is undefined because I have not set a value for my car.

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I've alerted my car.

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Boy hasn't got a family.

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That's why he's called on to find out what's your variable boys created.

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You can't always change the values later.

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So for example I've already declared a variable x.

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I can change that value from 27 any time variable has already been declared or created.

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Right so this I have now given the value I have now set a value for the variable.

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My car remember when I created it.

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I didn't create a set of value.

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It's always good to set a value if you know what the value should be but sometimes you don't always

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know.

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So I've said it variable.

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So the variable my car and have now come down here and giving it a value of reinke for that.

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So now alert for this alert comment let my car it will come up.

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Ring true.

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So let me see that run that ring from above because I am now giving it value.

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So variable can always be called twice.

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It has been declared so calling a variable or you need to do is called a name like it Don here.

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I've already declared the variable of my car so to call it does alert the message my car and then he

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shows up in the pop up window.

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Right so Im going to comment this out.

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All right Im just going to alert this variable here called first name.

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Also when you are calling your variables make sure you call them by their right name.

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For example if you notice a variable name here is come or case that is first and then the other part

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of its first letter is capital.

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If I came here and call the first name without a capital N the computer program programming language

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will not know what I'm talking about javascript would just throw up an error or say I don't know what

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you mean.

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Sorry.

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So you must name them or call them what you name them.

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For example here I've called variable X..

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If I come here and call a variable or PI case X it will not know what I'm talking about because the

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case is sensitive.

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So if I run this now it will come on but on defined because of not giving it a value.

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When I declared it or created it.

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So click on run

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comes up as defined so I can now go ahead later and then give it a value.

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K I have now given this variable here.

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The first new variable have now giving it a value of you.

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So give is now.

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Got to name value.

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So if I run a left first name it should come up.

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You do me so let me run that.

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All right so come on we you demi no longer says on defined because Eve has now got a value.

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Also once a variable has been declared or created you can always change the name.

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All it is is a container label.

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You can always change what you've got inside.

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So what you store can always change.

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So for example if I want to change this name from Demi to something else say to Jack has put Jack there.

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So I changed that to Jack save that.

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Run it.

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It's now coming up with the value of Jack.

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So I've changed.

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What's in the container so you can always change the variable once it's being declared you can change

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the value of the variable once it is been declared.

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So be careful that variable names are case sensitive.

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Okay I apologize.

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This video has gone on a bit longer than I expected.

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There was so much I wanted to cover.

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I do apologize.

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It's too long.

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Thank you so much for watching.

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I hope the video has made sense if it hasn't.

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Please feel free to contact me and I you now have some kind of understanding of what variables are how

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to create them.

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Also thank you so much for watching.

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Bye for now.