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We can use variables to store values in the getting started section, you learn to create and run a

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job, a program you ran, a fairly simple program that prints Hello, Java.

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Now, one more useful program is able to store information, and that's why in this lesson, you're

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going to learn to store values inside variables.

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First thing I'll need you to do is create a new Java project by yourself and call it Section two, then

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launch it from voice code.

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And inside the project, critical name variables Jebba and make sure the variables class has the main

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method.

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All right, what is a variable?

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A variable can store value.

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Think of a variable as some kind of box, each variable has a name, so I'll call this one food.

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This variable, this quote unquote, box can store values.

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This one store is a tax value.

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But it can also store an integer value, by the way, integer means hole number, the take home message

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is that a variable can store any type of value instead of make a variable in Java, you need to include

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three pieces of information, the type of value we can store, the name of the variable and the value

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itself.

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And to this code creates a variable called people, the variables of type int so we can only store numbers

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like the number two.

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Some inside main making into variable named people and set it equal to 20 different people.

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Is equal to 20 and don't forget your semicolon.

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Remember that every line of code in Java needs a semicolon at the end.

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Otherwise, your code is not going to run.

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And so now this variable stores the number 20.

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Now, I want to talk about the convention to naming variables and there's a specific way to name them,

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and it's called Lower Kemel case.

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In Java, the variable needs to start with a lowercase letter.

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The variable people starts with a lower case P, but what if we have more than one word like people

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on bus?

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In that case, you'll start with a lower case letter, but the words that follow must be upper case.

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Notice that people start to they lower case P.

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And on bus, half capital letters.

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This right here is the lower camel case format, and that's how you're supposed to name variables,

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if in my code I decide to rename this variable to people on Busse, I would have to use the lower Camil

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case format, people on bus, yet people on buses.

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Dulong I prefer saying passengers, so I'll rename the variable to passengers.

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Remember to write class names in Camil case, where each word is capitalized and joined together and

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always write variable names and lower camel case were the first word is lowercase, but the words that

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follow are capitalized.

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I highly encourage you to follow these conventions because it's what the professionals do and it makes

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your code clearer and easier to read.

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OK, so we talked about variables being able to store values, but you can actually print the value

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inside a variable.

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You created a variable called passengers and it stores the value 20.

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So using print line, you can print the variables value to the console system.

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Print line passengers.

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Now, you can go ahead and open up the terminal, compile your code using job C variables Java.

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And run the compiled code using Java variables.

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Sure enough, the value inside passengers is 20.

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Now, here's a similar code where I didn't name passed in your stores the value five instead of 20,

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then you printed the value inside passengers.

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Java is strongly typed once you define the valley type or verbal can only store values of that type.

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For example, you cannot stop text in an integer variable that's illegal, the value that you store

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needs to be consistent with the variable type.

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You try to store value that is different from the variable type, you will get a type mismatch.

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In other words, your codes not going to compile.

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So back to my code, I'm going to try to set passengers equal to some.

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Text value.

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Let's try to Kampala's.

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And I get an error in line three of my code and it says that string cannot be converted to it.

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This error is a result of trying to store text in an integer variable.

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And invariable can only store integer values like five, you cannot store text.

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So compiling this code and running it were good, by the way, in case you forgot, the reason I'm able

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to run these terminal commands so quick is because I'm using the up key to access previous terminal

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commands.

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You would have already seen this in the workbook one point one, as well as your very first quests.

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In any case, Java is case sensitive, which means Java discriminates between uppercase and lowercase

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letters, for example, passengers is not the same as capital passengers.

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I try to compile this, I would get an error in line four of my code and it tells me that Java does

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not recognize the variable capital passengers because you never made one.

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You must always stay consistent with letter cases.

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So we're going to fix this variable back to what it was.

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All right.

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Finally, you can set variables equal to each other if you set a variable equal to another, the variable

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copies of the value inside the first one, just like you're seeing here.

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So make an integer variable name bus tickets, remember that you need to write variables in lower camil

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case lower case B in the words that follow must be upper case bus tickets.

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Now, let's assume to enter the bus, every passenger needs one bus ticket.

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So there are as many bus tickets as there are passengers and bus tickets is equal to passengers.

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Now we're going to check the value inside bus tickets by printing it system dot out, dot print line

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bus tickets, I would expect this to print five, but let's double check Gervasi variables that Gever.

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Job of variables and as expected, it prints five bus tickets and five passengers.

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Great.

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Here's the code we have so far.

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By setting the bus tickets variable equal to passengers, it copies the value inside.

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In this lesson, you learn to store values inside variables, you stored the integer value five inside

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passengers and then you print it out using the print online function.

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You also learn that variables can only store values of their type.

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For example, you cannot store text in an integer variable.

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The last thing you learned was the set variables equal to each other.

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You set the bus ticket variable equal to passengers and it copied the value inside.