unable to validate user input in javascript

Question

I am trying to validate the user input in my the case the input is the color name entered by user, here is the code snippet

let valideColor = false;

do{

      const selected_color = $('#SelectedColorPicker').val();

        if (selected_color === '') {
            console.log('Not valid')
        }
        else {
            validColor = true;
        }

}while(!validColor)

the code above produces an infinite loop leading my browser to crash, I would appreciate if anyone can tell me where the problem is .

You could use required attribute, or an event, more like change event to check that. And change const to let or var... — DontVoteMeDown
– DontVoteMeDown, Commented Sep 5, 2019 at 20:01
the goal is to display a modal box instead of console.log when the input is not valid — Kenzo
– Kenzo, Commented Sep 5, 2019 at 20:08

Robin Zigmond · Accepted Answer · 2019-09-05 20:03:33Z

4

You've got an infinite loop because you're running code continuously in a loop, not giving the user a chance to enter any input - when user input would be the only way to make validColor true and therefore break out of the loop.

A loop is totally the wrong approach here. You only need check at certain points, presumably when the user tries to submit whatever form this input is part of. So you should do something like this:

$("#idOfMyForm").submit(function(e) {
    const selected_color = $('#SelectedColorPicker').val();

    if (selected_color === '') {
        console.log('Not valid');
        e.preventDefault();
    }
});

to warn the user (although of course a mere console.log will not be noticeable to anyone who doesn't have the browser console open, so not the vast majority of users), and stop the form submitting.

answered Sep 5, 2019 at 20:03

Robin Zigmond

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Comments

mzparacha · Accepted Answer · 2019-09-05 20:05:38Z

0

You can use this

let validColor = false
  $('#SelectedColorPicker').on("change",function(){
      if ($(this).val() === '') {
        console.log('Not valid')
      }
      else {
        validColor = true;
      }

  });

answered Sep 5, 2019 at 20:05

mzparacha

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Comments

user2258948 · Accepted Answer · 2019-09-05 20:11:34Z

0

You can use input

$('#SelectedColorPicker').on("input", function() {
   var selected_color = this.value;
   console.log(selected_color);
});

answered Sep 5, 2019 at 20:11

user2258948

1

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