JavaScript arrays checking

Question

I'm going to have unknown number of prompt dialogs.
I will have their number after some user actions, but I want to create them, display them and at the end check if some of them is null(empty).
I'm looking for ideas how to do that.
Can I do it without loop?
Something like:

arrayName[] = prompt("Enter text");
arrayName[] = prompt("Enter text");
arrayName[] = prompt("Enter text");
arrayName[] = prompt("Enter text");

and then check if some of them is empty?
And can I declare array in shorthand way like in PHP and C#?

array[]
array[]

"Can I do it without loop?" Why would you want to? This is what loops are for. — T.J. Crowder
– T.J. Crowder, Commented Apr 23, 2013 at 9:41
is it a value passed from the server? or a count calculated at the client side or decided based on a value entered by the user in one of the prompts — Arun P Johny
– Arun P Johny, Commented Apr 23, 2013 at 9:50
Nope. The value is typed by the user. I wanted to escape the loop, because I have to send an AJAX request to the server for each prompt in the array and I just wanted to ignore the empty prompts. — Paul Reed
– Paul Reed, Commented Apr 23, 2013 at 10:07

mplungjan · Accepted Answer · 2013-04-23 09:48:47Z

1

Yes you can and you can use =[] to create the array

var arrayName=[];
arrayName.push(prompt("Enter text"));
arrayName.push(prompt("Enter text"));
arrayName.push(prompt("Enter text"));
arrayName.push(prompt("Enter text"));
arrayName.push(prompt("Enter text"));

for (var i=0;i<arrayNames.length;i++) {
  if (arrayName[i]==null) alert("You did not answer "+(i+1))
}

If you can use a loop it is of course simpler. Please tell use why you do not want to use a loop?

var arrayName=[];
for (var i=0;i<unknownNumberOfPrompts;i++) {
  var answer = prompt("Enter text","");
  if (answer) arrayName.push(answer);
}
if (arrayname.length>0) {
  // something was answered
}

edited Apr 23, 2013 at 9:48

answered Apr 23, 2013 at 9:41

mplungjan

180k29 gold badges183 silver badges246 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

T.J. Crowder Over a year ago

"I'm going to have unknown number of prompt dialogs." (my emphasis)

mplungjan Over a year ago

Yes, my code will check any number of prompts assuming each prompt is specified as arrayName.push(prompt("Enter text"));

T.J. Crowder Over a year ago

But again, it's an unknown number. So clearly they can't just be written in the source; that would be known. (He also asked to do this "without loop" for some completely unknown reason...) Anyway, I leave you and the OP to it. If the question ever makes sense, he's in good hands getting it answered. :-)

Paul Reed Over a year ago

I will create a loop and it will set the correct number of arrays.

mplungjan Over a year ago

It may be unknown to the script at the time of writing and receive an unknown number of prompts from a cfout or php echo or whatever

Collectives™ on Stack Overflow

JavaScript arrays checking

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related