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Java Java Basics Perfecting the Prototype Looping until the value passes

Posted by Gary Curkan
Gary Curkan
497 Points

I don't understand do-while loops 

String response;
        do {
          response = ("Do you understand do while loops?"); 

        }

I don't understand how to make the response "no," so the program can keep running; or how to make it yes to stop it. How do I continually prompt the user? I could print something out that says "try again," but that wouldn't just make the computer decide to just print it out again.

This is challenge task 2 of 3 for Java Basics

1 Answer

Kevin Faust
Kevin Faust
15,353 Points
Kevin Faust
Kevin Faust
15,353 Points

First, remember we are taking input from user so it's 

response = console.readLine("Do you understand do while loops?");

And secondly, add this: 

while (response == "No");

So the "do" block of code runs for the first time. We take input from user. While the response is equal to "No", then, the loop will run again and again and again until the response variable is equal to anything other than "No"

String response;

do {

response = console.readLine("Do you understand do while loops?");

} while (response.equals("No"));

So as you can see above, the "do" block will keep on running as long as the while statement is true

Gary Curkan
Gary Curkan
497 Points

Thanks for the response! That makes a lot more sense! What makes the statement true though? Because I typed "no"?

Kevin Faust
Kevin Faust
15,353 Points
Kevin Faust
Kevin Faust
15,353 Points

Yup. the statement is true when you type "No". not "no". Java is case sensitive so the two are not the same.

But let's say we type in "No"

Then our while loop will look like this: 

("No" == "No")

Since they are equal to each other, the statement is true and the loop ends.