how to check for jQuery's FIND result

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Check if element exists in jQuery [duplicate] 8 answers

Is there an “exists” function for jQuery? 36 answers

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You were very close!

Simply check for selected.length instead of selected .

Demo for parent selection

$(document).ready(function() {
  var parent = $(this).find(".parent");
  if (parent) {
    var selected = parent.find("div.selected");
    if (selected.length) {
      selected.css({
        "color": "blue",
        "border": "2px solid blue"
      });
    } else {
      parent.css({
        "color": "red",
        "border": "2px solid red"
      });
    }
  }
});

.ancestors * {
  display: block;
  border: 2px solid lightgrey;
  color: lightgrey;
  padding: 5px;
  margin: 15px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

<script>
</script>

<div class="parent"> Parent Box
  <div class="noselected"> Box A </div>
  <div class="notselected"> Box B </div>
</div>

---

$(document).ready(function() {
  var parent = $(this).find(".parent");
  // check for the length property of the jquery object to get the number of elements matched
  if (parent.length != 0) {
    var selected = parent.find("div.selected");
    // same goes here
    if (selected.length != 0) {
      selected.css({
        "color": "blue",
        "border": "2px solid blue"
      });
    } else {
      parent.css({
        "color": "red",
        "border": "2px solid red"
      });
    }
  }
});

.ancestors * {
  display: block;
  border: 2px solid lightgrey;
  color: lightgrey;
  padding: 5px;
  margin: 15px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

<div class="ancestors">
  <div class="parent"> Parent Box
    <div class="notselected"> Box A </div>
    <div class="notselected"> Box B </div>
  </div>
</div>

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