While taking this challenge should I still insert an if statement? Knock Knock

Hi Alexander,

An if statement could certainly check that a test is passed, yes. However, it is not a "loop" - the test happens only once.

The question says:

We want to move that prompting code into a do while loop. Wrap the code into a do while code block and check in the while condition to see if who is "banana" so that the loop continues.

So, we need a do ... while loop, it says. We have three lines of code already to help us:

// Person A asks:
console.printf("Knock Knock.\n");

// Person B asks and Person A's response is stored in the String who:
String who = console.readLine("Who's there?  ");

// Person B responds:
console.printf("%s who?\n", who);

So, we need to deal with the first scenario - the answer being "banana". This means we need to loop back through the whole knock-knock sequence. The sequence must run at least once before the test can be applied. This is why the do ... while loop is best for this purpose.

do {
    console.printf("Knock Knock.\n");
    String who = console.readLine("Who's there?  ");
    console.printf("%s who?\n", who);
} while (who.equals("banana"));

This takes you through the required sequence of asking the question and getting the answer, it then loops back to the beginning if the answer given is equal to "banana". This will carry on as long as that answer is given.

That's not all, though ... the hint given let's us aware of this. There's a scoping issue:

HINT: Remember to move your who declaration outside of the do block so that it can be accessed.

All that means is that the initial declaration of the variable who needs to happen before the inside of the loop. Like this:

String who;

do {
    console.printf("Knock Knock.\n");
    who = console.readLine("Who's there?  ");
    console.printf("%s who?\n", who);
} while (who.equals("banana"));

That should work for you now.

Steve.