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We can use scanner to make our applications interactive.

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We've already built many applications using the five main data types.

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Br view they are int to store whole numbers long for large real numbers, double for decimals, car

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for characters and string for text.

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But there is a small issue with the apps you've built so far, and that is that they've been static.

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In other words, you've been storing predefined values.

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Now in the real world, you want to make a dynamic application where values come from, the user.

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Like here, for example, the application is asking the user questions and the user answers by submitting

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values through the terminal.

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And once the user answers every question, the application responds, this application is fully interactive

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because the application and the user are communicating with each other.

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So in this lesson, you're going to use scanner to get values from the user.

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First thing I need you to do is create in your class, so inside the Section two project to make a new

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file named Survey Java and inside the survey class, make sure it has the main method.

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Scanner waits for the user to enter a value in the terminal.

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In the survey app, you will ask the user questions such as How old are you?

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And now Scanner needs to wait for the user to enter an integer.

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We do that with scanned next minute.

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And now the user must go to the terminal type a number and press enter.

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Once the user presses enter, scanned next and picks up the integer and stores it in the variable.

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We need to import scanner in order to use it.

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Scanner comes from a package called Java Util.

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So from Java, you tell we can import scanner.

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And notice that we import at the very top.

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So back to our code, we're going to import scanner, to the survey class import and from Java, you

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tell we're going to import scanner.

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Now we can access scanner inside the survey class.

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Simple as that.

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And so the next step is to set up scanners so that it can receive input from the user.

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So we need to make a scanner variable, and that involves three steps.

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The variable must be F-Type's scanner, the variable name I usually call it scan, but you can call

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it anything and you're going to set the variable equal to a new scanner such that this scanner can get

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input from the system system not in.

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Scanner.

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Skin.

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Is equal to a new scanner instance.

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That's going to receive input from the system system in.

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And now we're going to use scanner to get a values from the user.

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Scanner has different methods that we can leverage to get values from the user.

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And next line is one of them.

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Next line waits for the user to enter a string.

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So we're going to start by giving the user a warm welcome.

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So system died out the bright line.

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Welcome, thank you for taking the survey.

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Then we'll say system.

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Dot out dot print line.

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What is your name?

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All right.

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Let's compile the code and run this.

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As you can see, this only prints two messages, then the app terminates.

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We need to cull Skin Dot next line so that it can wait for the user to enter a stream value.

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All right, let's try it out.

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Compile your code.

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Run it.

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And check it out, it waits for me to enter a string.

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I'm going to right, Sam.

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And there you go.

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What's happening is that Scandal Next line waits for the user to enter a string.

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The user being me and the user went to the terminal and typed, Sam.

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And once the user presses enter scan, the next line picks up the value.

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But to be able to use this value in the future, we have to store it inside a variable.

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So what I'm going to do is say string name is equal to scandal.

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Next line.

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So now, when the user enters their answer, scanned, the next line gets the string of value and stores

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it in the variable name.

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Next, stubble is another method we can call from Skinner.

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This one waits for the user to enter a double value.

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So now we're going to ask the user how much money they would spend on coffee.

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So System died out die print line.

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Money, do you spend?

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On coffee.

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And now, Renee, you stand up next, double to wait for the user to enter a double.

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So we'll say double.

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Coffee price.

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Is equal to scan next double.

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All right, we're compiling our code.

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And running it.

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What is your name, Sam?

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How much money do you spend on coffee?

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Let's say a dollar fifty.

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So what happens is it picks up the value and stores it in a variable coffee price.

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First, the programs they use or how much money they spend on coffee scanned next level, wait for the

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user to enter a decimal.

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It picks it up and stores it in a variable.

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All right.

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For more practice, we're going to ask the user how much money they spend on fast food system dart out

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dart line.

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How much money?

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Do you spend on fast food?

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And you're going to store the user's answer in a variable double food price is equal to scan Dot next

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double.

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What is your name, Sam?

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How much money do you spend on coffee?

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A dollar fifty?

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How much money do you spend on fast food will say four dollars and fifty cents.

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And once again scanned next, I will wait for the user to enter a decimal.

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It picks it up and stores it in a variable.

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Next is another method you can call from scanner.

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And this one, as you could probably guess, it waits for the user to enter an integer.

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So to start ominous, these are how many times a week they buy coffee and how many times a week they

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buy fast food.

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So system dot out dot print line.

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How many times a week?

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Do you buy coffee?

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And I'm going to store the user's answers in a variable coffee amount.

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And we're going to set that equal to scan next.

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It.

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Then we'll do the same thing here, system dot out dot print line.

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How many times a week do you buy fast food?

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And we'll store the user's answer in a variable food amount.

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And we're going to get the user's answer by waiting for the next it's.

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All right.

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Recompile the code and run it.

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What is your name?

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Sam?

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How much money you spend on coffee, a dollar?

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Fifty four dollars and fifty cents?

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How many times a week do you buy coffee?

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Five.

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Fast food seven.

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All right.

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This app is shaping up pretty well.

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The first scandal, an accident, waits for the user to answer the key question.

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Then it picks up the value in stories that in the amount, the second scanned on and waits for the user

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to answer the fast food question.

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Then it picks up the value and stores it in food amounts.

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And now every variable stories is one of the users answers.

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You might be wondering what if the user puts a wrong value?

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And the second question, for example, let me just rerun my code.

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When I put in the first answer and now here, what if I put a string, when next they will expect a

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decimal?

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Let's try up.

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And Java throws an error and it crashes.

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Next, we'll expect to decimal notice drink, and so if you enter a string next double doesn't know

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what to do with it.

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So the application crashes.

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You should close the scanner when you're done with it.

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Keeping scanner open is a memory leak.

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When you're done with it, you can close it with scanned clubs.

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Scan Duclos.

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Now, if you scroll up notice that the warning is gone.

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Let's recap in this lesson, you learn to use scanner to get values from the user.

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Next line waits for the user to enter a string value.

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And once the user presses enter scanned, our next line picks up the string and stores it in the variable.

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Next double waits for the user to enter a double value, and once the user presses enter scan, the

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next double picks up the double and stores it in the variable.

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Next in, wait for the user to enter an into value.

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And once the user presses enter scanned next and picks up the end and stores it in the variable.

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Restore it every value that the user entered.

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So what do we do now?

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Stick around for part two.