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Before we start, did you try solving the workbook yourself?

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If not, please click the link in the resources folder and follow the instructions for this workbook.

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This video will present the solution to workbook 3.2.

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I'm also going to show you how to visualize the runtime in VS code.

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So please make sure that you launch the exact folder that contains your java file.

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Do not under any circumstance launch all of the resources at once.

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If your file explorer looks like this, you will not be able to visualize the runtime.

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So please close this atrocity and launch the exact folder that contains your file.

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Anyways, let us begin.

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You start with $100 and your child wants you to purchase them a toy car.

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So first we need to check if we have enough money to purchase this car.

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Can we afford it?

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So we'll say if the wallet if the money I have in my wallet is greater than or equal to the price of

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the toy car, then we are going to print.

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Sure.

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Let's add a new line.

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And then we need to pay for the toy car.

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So we need to say wallet minus equal toy car.

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So we're updating the variable on the left by subtracting from it the value on the right.

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From the wallet.

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We are subtracting the toy car and now we can say otherwise.

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If we cannot afford the toy car, we're going to print.

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Whatever this message is.

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Sorry, I only have wallet left.

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And I think we're good to go.

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Let us visualize the runtime.

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Let's put breakpoints everywhere.

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All right.

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Debug.

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So first.

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It creates two variables wallet, which equals 100 and toy car which equals 599.

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Now we reach the if statement which will only execute if wallet is greater than or equal to toy car.

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Wallet is 100, Toy car is 599.

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This condition is true.

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So the if statement is indeed going to execute it prints.

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Sure.

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Followed by a new line.

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And here we're updating the variable on the left by subtracting from it the value on the right.

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So $100 -599.

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But if I press continue.

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It terminates the runtime and we don't get to see the updated variable here.

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That is a shame.

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Let's do it again.

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All right.

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Stepping through it again, it creates two variables here.

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It's just going to print a message.

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And this condition is true.

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So the if statement executes.

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Prince Sure.

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And now, because this is the last thing that is going to run, we don't want to press continue.

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We want to just step over this line.

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So press the step over button.

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And now we can see the updated variable.

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First, we had $100.

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Now we have $94.01 and toy car obviously is still 599 Press continue and it terminates the runtime.

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So what I'm going to do is let you pause the video and write the code for this one yourself.

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All right.

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I hope you figured it out.

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Let's walk through the whole runtime.

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Let me just add some breakpoints over here as well.

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OC.

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So over here, let's just step through everything.

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Wallet 100 is clearly bigger than a toy car of 599.

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This condition is true.

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So the if statement executes prints?

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Sure.

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And here the variable on the left is going to update by subtracting the value on the right.

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Let's see it in action.

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Now wallet is $94.01.

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And now it continues to the next breakpoint.

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So now if I continue here.

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The Nike shoes are 95.99 here at prints.

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Can I get these Nike shoes?

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All right.

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Now we reach the if statement, which will only execute if wallet is greater than or equal to the Nike

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shoes.

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But here we can see that wallet is $94.01, whereas the Nike shoes are 9599.

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So this condition is going to turn out to be false.

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The statement will not execute.

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So we default to the statement and it's going to print.

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Sorry, I only have wallet left.

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$94.01.

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Now let's run a test case where this is 8999.

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I'll remove all of these breakpoints.

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And we will start by visualizing the runtime over here.

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This time, the Nike shoes are only $89, but we have $94 in $0.01 in our wallet.

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So this is indeed going to execute.

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And after we purchase the Nike shoes, we're going to step over this line because it's the last thing

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that will run.

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And we want to visualize the update in our wallet variable.

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It's going to update by subtracting the value on the right.

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94 -89.99 is $4.02.

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So after purchasing a toy car and Nike shoes, we have $4.02 left in our wallet.

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Beautiful.

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Let's clean up.

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If you want to remove the breakpoints, press the x button.

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And if you want to rerun your code normally using terminal commands, of course we can use the familiar

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Java Sea Java Java Command to compile our code followed by Java Java Mart.

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All right.