Compare input values using jQuery

Question

I have a form with 3 input file fields. I want to make sure that they do not upload the same document twice. Right now my code is as follows:

$(':input.File').each(function() {
    if ($(this).val() == T) {
        $this.after('<br/><span class="error">Duplicate</span>');
    }
})

The code works but my issue is that it always throws the error because it is comparing against itself. It identifies all file fields when I want it to compare all file fields but itself.

Is there a way to exclude the field being compared against? Essentially I want to check all the file field value except for the $(this) field.

I must be being thick but...where does T come from?

GrahamTheDev
– GrahamTheDev

2014-04-01 23:15:35 +00:00
Commented Apr 1, 2014 at 23:15 — GrahamTheDev
– GrahamTheDev, Commented Apr 1, 2014 at 23:15

informatik01 · Accepted Answer · 2018-09-28 14:15:22Z

2

If you know there is always going to be at least one duplicate, why not just allow one duplicate?

i = 0;
$(':input.File').each(function() {
    if ($(this).val() == T && i != 0) {
        $this.after('<br/><span class="error">Duplicate</span>');
    }

    i++;
})

edited Sep 28, 2018 at 14:15

informatik01

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answered Apr 1, 2014 at 23:17

Stacks

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Comments

Adam Merrifield · Accepted Answer · 2014-04-01 23:17:52Z

1

Make an empty array, then go through each field and check if that field is in the array if not add it.

var arr = [];

$(':input.File').each(function(){
    if(arr.indexOf($(this).val()) > -1){
        $(this).after("<br/><span class='error'>Duplicate</span> ");
    }else{
        arr.push($(this).val());
    }
})

answered Apr 1, 2014 at 23:17

Adam Merrifield

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2 Comments

Ruan Mendes Over a year ago

Why the downvote? +1 to compensate, since it's actually what I suggested but with an array

Adam Merrifield Over a year ago

@JuanMendes I was wondering the same thing, but it's gone now.

Ruan Mendes · Accepted Answer · 2014-04-01 23:20:01Z

1

You can use a map to keep track of what values exist

(function(){
  var exists = {};
  $(':input.File').each(function() {
    if(exists[$(this).val()]){
      $this.after("<br/><span class='error'>Duplicate</span> ");
    } else {
      exists[$(this).val()] = true;
    }
  });
})()

answered Apr 1, 2014 at 23:20

Ruan Mendes

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Comments

Community · Accepted Answer · 2017-05-23 11:50:50Z

0

I have a feeling this is what you are looking for:

jQuery: exclude $(this) from selector

In order to give you a more specific answer, I'd need a bit more code context. (IE. what is T, how it that code reached, etc.)

edited May 23, 2017 at 11:50

CommunityBot

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answered Apr 1, 2014 at 23:16

Robert Messerle

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Comments

Bastien Ho · Accepted Answer · 2020-09-25 12:52:37Z

0

For a checkup after each user action:

$('input[type=file]').change(function(){
     $('input[type=file][value="'+$(this).val()+'"]').not(this).after("<br/><span class='error'>Duplicate</span> ");
});

answered Sep 25, 2020 at 12:52

Bastien Ho

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