auto select checkboxes by retrieving their value JavaScript

问题

I got some difficulties with one point since 1 week, I have 2 arrays, and I want to auto select checkboxes by retrieving the value inside one of the array.

First of all, I have a loop which create some checkboxes based on the first array choices[].

Every time I check one a checkbox, a text field is updated with a separator. "$#"

I save this text field by my own. But now I have an array with some values as string target[].

I want to auto select checkboxes which has his value inside the array target[]. So if I change a value in target[], and I refresh, the checkbox concerned will be automaticly selected.

Here is a snippet to see how it looks like now. PLease update it to answer.

I would prefer JavaScript but I deseperated so if you have Jquery it would be ok.

//array of options
var choices = new Array();
choices[0] = "January";
choices[1] = "February";
choices[2] = "March";
choices[3] = "April";
choices[4] = "May";
choices[5] = "Juny";
choices[6] = "July";
choices[7] = "August";
choices[8] = "September";
choices[9] = "October";
choices[10] = "November";
choices[11] = "December";

var target = new Array()
target[0] = "3";
target[1] = "8";

var cbh = document.getElementById('checkboxes');
var val = '';
var cap = "";

var j = "";
var t = document.getElementById('t');

// the loop is creating the checkboxes with name, value...
for (var i in choices) {
  //Name of checkboxes are their number so I convert the i into a string. 
  j = i.toString();

  val = j;
  //cap will be the value/text of choices[i]
  var cb = document.createElement('input');
  var label = document.createElement("label");

  cap = choices[i];
  var text = document.createTextNode(cap);
  cb.type = 'checkbox';
  cbh.appendChild(cb);
  cb.name = cap;
  cb.value = val;
  label.appendChild(cb);
  label.appendChild(text);
  cbh.appendChild(label);
  cb.addEventListener('click', updateText)

}

function updateText() {
  t.value = [null, ...document.querySelectorAll('#checkboxes [type="checkbox"]')].reduce((s, el) => el && el.checked ? s = (s || '') + el.value + '$#' : s || '')
}

* {
  box-sizing: border-box;
}

#data {
  padding: 5px;
  width: 100vw;
}

.multiselect {
  overflow: visible;
  padding: 0;
  padding-left: 1px;
  border: none;
  background-color: #eee;
  width: 100vw;
  white-space: normal;
  height: 50px;
}

.checkboxes {
  height: 100px;
  width: 100px;
  border: 1px solid #000;
  background-color: white;
  margin-left: -1px;
  display: inline-block;
}

label {
  display: inline-block;
  border: 1px grey solid;
  padding: 5px;
}

<form>
  <div id="data">
    <div class="multiselect">
      <div id="c_b">
        <div id="checkboxes">
        </div>
      </div>
    </div>
  </div>
</form>

<textarea id="t"></textarea>

来源：https://stackoverflow.com/questions/44385952/auto-select-checkboxes-by-retrieving-their-value-javascript

标签

javascript

jquery

html

arrays

checkbox