Ensure all values are used

Question

I am trying to make sure that all values, except one, is used in my drop downs - but there is an error, where its possible to cheat on it. And I am not sure why.

You can try it on: http://jsfiddle.net/BSxXk/2/ and use the values: 4 2 3 4 - This should produce an error since 1 is not used. I am using Firefox on Windows.

HTML:

<select name="answer" class="question-answer">
    <option value="-1">Choose value</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
</select>

<select name="answer" class="question-answer">
    <option value="-1">Choose value</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
</select>

<select name="answer" class="question-answer">
    <option value="-1">Choose value</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
</select>

<select name="answer" class="question-answer">
    <option value="-1">Choose value</option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
    <option value="4">4</option>
</select>

<div id="result">d</div>

<button id="submit">Test</button>

JQuery:

var valid_values = [1, 2, 3, 4];

$("#submit").on("click", function(event) {
    event.preventDefault();
    var values = $.unique($('select.question-answer').map(function() {
        var value = $(this).val();
        if (value === "-1") {
            return;
        }
        return value;
    }));
    if(values.length === valid_values.length) {
       $("#result").html("Valid");
    } else {
        $("#result").html("All values (1-4) should be used in answering the question.");
    }
});

Screenshot of error. 1 is not used, but says valid:

enter image description here

Please note this is a follow-up of my previous question: Make sure all values are used in drop downs

Your selects should have different names. Also, your fiddle has a typo `$("#subumit")` — j08691, Mar 12 '14 at 15:34
Here is a correct fiddle with the posted code http://jsfiddle.net/BSxXk/2/ and it works fine — Huangism, Mar 12 '14 at 15:36
I use the same name for getting an array of results in a POST. I got 4 x — janhartmann, Mar 12 '14 at 15:37

Huangism · Accepted Answer · 2014-03-12T16:08:10.620

0

Trick question, code in the fiddle does not match code posted. The fiddle works fine with the posted code

http://jsfiddle.net/BSxXk/2/

var valid_values = [1, 2, 3, 4];

$("#submit").on("click", function(event) {
    event.preventDefault();
    var values = $.unique($('select.question-answer').map(function() {
        var value = $(this).val();
        if (value === "-1") {
            return;
        }
        return value;
    }));
    if(values.length === valid_values.length) {
       $("#result").html("Valid");
    } else {
        $("#result").html("All values (1-4) should be used in answering the question.");
    }
});

UPDATE

using jquery 1.10.1 works for me http://jsfiddle.net/BSxXk/5/ using anything above, does not work for me

I still think the use of unique is incorrect here, because $.unique only works on DOM elements https://api.jquery.com/jQuery.unique/ the map function on the question-answer only returns numbers so it makes perfect sense that unique does not work

edited Mar 12 '14 at 16:08

answered Mar 12 '14 at 15:38

Huangism

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See http://jsfiddle.net/BSxXk/2/ and pick values 4, 2, 3, 4 and click Test. This produce "valid", while its not - 1 is not used. – janhartmann Mar 12 '14 at 15:39
@meep How do you get this result? Works as expected for me – A. Wolff Mar 12 '14 at 15:52
well then it looks like your last question's answer is incorrect then – Huangism Mar 12 '14 at 15:53
@A.Wolff which browser are you using? I get valid with OP's input which should be invalid, using FF on mac – Huangism Mar 12 '14 at 15:54
chrome win7 on my side – A. Wolff Mar 12 '14 at 15:57
I'm using Firefox on Windows. Odd. Also see screenshot in question – janhartmann Mar 12 '14 at 15:58
I am guessing the issue is at unique, look at http://stackoverflow.com/questions/11246758/how-to-get-unique-values-in-a-array perhaps you should find unique in the values array – Huangism Mar 12 '14 at 16:04
Can you provide an example? – janhartmann Mar 12 '14 at 16:14
The link I provided already has examples, also see my update in my answer – Huangism Mar 12 '14 at 16:15
Using the examples in the post, it seems to work :-) – janhartmann Mar 12 '14 at 16:32

score 0 · Answer 2 · answered Mar 12 '14 at 15:45

Try this: http://jsbin.com/ciwaq/1/edit

$('button').click(function(){

  var values = ['1','2','3','4'];
  var selectValues = [];

  $('select').each(function(){
    selectValues.push($(this).val());
  });

  if($(values).not($(values).not(selectValues).get()).get().length !== values.length) {
     $('#result').html('All values are not used');
  }
  else {
    $('#result').html('All values ARE USED :)');
  }

});

Ensure all values are used

2 Answers2

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