Should I use a while or a do while loop if I want a prompt to loop till valid answer?

[hrstissiaopai]

I have previously said that I am making a game that is text based with javascript, and I got a bunch of helpful replies, which told me to use a loop, but I do not know what loop exactly to use and how. Here is the context that I am using it in:

var turn=prompt("Where do you want to turn? Left or right?");
if (turn=="left"){
window.alert("You chose to turn left!");
window.location="somepage1.html";
}
if (turn=="right"){
window.alert("You chose to turn right!");
window.location="somepage2.html";

Please help. Thanks in advance.

[divideby0]

The type of loop depends on where you need/want to test. The while loop tests at the top, so the loop body may or may not be entered depending on the test condition. The do while tests at the bottom and will enter the loop body at least once. The for loop can behave either way depending on how it's initialized.

With your code, maybe something like

var turn = prompt(...);

while(test conditions are false)
{
   turn = prompt(...);
}

// manipulate turn's value here

Another thing is javascript treats LEFT, left, LEft, etc as different strings. To deal with that, you can use turn.toLowerCas e() or turn.toUpperCas e() in your test conditions.