How to remove duplicate li items only for each ul item using javascript html - Jquery

Godwin
December 6, 2022
105 views
2 votes
3 Answers

I have a dynamically generated navigation structure shown. Each location has storetypes generated from the stores at the location.

I need to remove duplicates per location so that groceries can appear in both locations. I tried the common jquery solution below which removes duplicates but it results in each storetype appearing only in one location.

var seen = {};
$("ul#storetypes").find("li").each(function(index, html_obj) {
  txt = $(this).text().toLowerCase();

  if (seen[txt]) {
    $(this).remove();
  } else {
    seen[txt] = true;
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul class="menu">
  <li>Location 1
    <ul id="storetypes" class="sub-menu">
      <li>groceries</li>
      <li>cakes</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
  <li>Location 2
    <ul class="sub-menu">
      <li>groceries</li>
      <li>motor spares</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
</ul>

Answers

what you did is correct, but just do it for every <ul>.

$("ul.storetypes").each(function() {
  var seen = {};
  $(this).find("li").each(function(index, html_obj) {
    txt = $(this).text().toLowerCase();
    if (seen[txt]) {
      $(this).remove();
    } else {
      seen[txt] = true;
    }
  });
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul class="menu">
  <li>Location 1
    <ul class="sub-menu storetypes">
      <li>groceries</li>
      <li>cakes</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
  <li>Location 2
    <ul class="sub-menu storetypes">
      <li>groceries</li>
      <li>motor spares</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
</ul>

You just need to target your top-level iteration at each sub-list.

Then iterate its children and remove duplicates.

Also, you don’t need jQuery.

document.querySelectorAll(".sub-menu").forEach((list) => {
  const seen = new Set();
  list.querySelectorAll(":scope > li").forEach((item) => {
    const text = item.textContent.trim();
    if (seen.has(text)) {
      item.remove();
    } else {
      seen.add(text);
    }
  });
});

<ul class="menu">
  <li>Location 1
    <ul id="storetypes" class="sub-menu">
      <li>groceries</li>
      <li>cakes</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
  <li>Location 2
    <ul class="sub-menu">
      <li>groceries</li>
      <li>motor spares</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
</ul>

You can do it like this:

$("ul.sub-menu li").each(function(index, html_obj) {
  if ($(this).prevAll(":contains(" + $(this).text() + ")").length > 0) {
    $(this).remove();
  }
});

This will look into each .sub-menu and see if any ‘li’ exist already with the same text, and remove the duplicated.

Demo

$("ul.sub-menu li").each(function(index, html_obj) {
  if ($(this).prevAll(":contains(" + $(this).text() + ")").length > 0) {
    $(this).remove();
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul class="menu">
  <li>Location 1
    <ul id="storetypes" class="sub-menu">
      <li>groceries</li>
      <li>cakes</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
  <li>Location 2
    <ul class="sub-menu">
      <li>groceries</li>
      <li>motor spares</li>
      <li>motor spares</li>
      <li>groceries</li>
    </ul>
  </li>
</ul>

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How to remove duplicate li items only for each ul item using javascript html – Jquery

Answers