How To Add Remove List Items In Javascript – Simple Examples

Welcome to a quick tutorial on how to add and remove list items in Javascript. Need to dynamically update an HTML list in Javascript?

To add a list item in Javascript:

  1. Create a new list item – var li = document.createElement("li"); li.innerHTML = "Item";
  2. Append it to the list – document.getElementById("LIST").appendChild(li);

To remove a list item in Javascript:

  1. Get all the list items – var all = document.querySelectorAll("#LIST li");
  2. Remove the corresponding item – document.getElementById("LIST").removeChild(all[0]);

That covers the basics, but read on for more examples!

ⓘ I have included a zip file with all the source code at the start of this tutorial, so you don’t have to copy-paste everything… Or if you just want to dive straight in.

 

 

REAL QUICK SLIDES

 

TABLE OF CONTENTS

Download & Notes List Items Useful Bits & Links
The End

 

DOWNLOAD & NOTES

Firstly, here is the download link to the example code as promised.

 

EXAMPLE CODE DOWNLOAD

Click here to download all the example source code, I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

QUICK NOTES

If you spot a bug, please feel free to comment below. I try to answer questions too, but it is one person versus the entire world… If you need answers urgently, please check out my list of websites to get help with programming.

 

 

JAVASCRIPT LIST ITEMS

All right, let us now get into the examples of how to add and remove HTML list items in Javascript.

 

1) CREATE LIST ITEM ELEMENT & APPEND

1-create-element.html
<!-- (A) HTML LIST -->
<ol id="demoA">
  <li>First</li>
  <li>Second</li>
</ol>
 
<!-- (B) JAVASCRIPT ADD -->
<script>
function addItem () {
  // (B1) CREATE NEW LIST ITEM
  var item = document.createElement("li");
  item.innerHTML = "New";

  // (B2) APPEND TO LIST
  document.getElementById("demoA").appendChild(item);
}
</script>
<input type="button" value="Add Item" onclick="addItem()"/>
  1. First
  2. Second

This is the “full example” of the snippet in the introduction. Add new items to an HTML list is that simple – Just create a new list item, and append it to the list.

 

 

2) APPEND POSITION

2-insert-position.html
<!-- (A) HTML LIST -->
<ol id="demoB">
  <li>First</li>
  <li>Second</li>
</ol>
 
<!-- (B) JAVASCRIPT ADD -->
<script>
function addItemPos (top) {
  // (B1) CREATE NEW LIST ITEM
  var item = document.createElement("li");
  item.innerHTML = "New";
 
  // (B2) APPEND ITEM TO TOP
  if (top) {
    document.getElementById("demoB").insertAdjacentElement('afterbegin', item);
  }
 
  // (B3) IN THE MIDDLE
  else {
    var allItems = document.querySelectorAll("#demoB li");
    var allLength = allItems.length;
    var middle = Math.ceil(allLength/2) - 1;
    if (middle<0) { middle = 0; }
    allItems[middle].insertAdjacentElement('afterend', item);
  }
}
</script>
<input type="button" value="Add Top" onclick="addItemPos(1)"/>
<input type="button" value="Add Middle" onclick="addItemPos()"/>
  1. First
  2. Second

The previous example will always append the new list item to the bottom of the list. So how do we insert to the top or somewhere in the middle? Use insertAdjacentElement() to help you do the “precise insert”.

 

 

3) ALTERNATIVE – APPEND HTML STRING

3-insert-html.html
<!-- (A) HTML LIST -->
<ol id="demoC">
  <li>First</li>
  <li>Second</li>
</ol>
 
<!-- (B) JAVASCRIPT ADD -->
<script>
function addItemHTML () {
  document.getElementById("demoC").innerHTML += "<li>New</li>";
}
</script>
<input type="button" value="Add Item" onclick="addItemHTML()"/>
  1. First
  2. Second

For you guys who somehow don’t like the “object-oriented” way of creating HTML elements – We can also directly append an HTML string to the existing list.

 

4) REMOVE LIST ITEM

4-remove-item.html
<!-- (A) HTML LIST -->
<ol id="demoD">
  <li>First</li>
  <li>Second</li>
  <li>Third</li>
  <li>Forth</li>
</ol>
 
<!-- (B) JAVASCRIPT REMOVE -->
<script>
function delItem (first) {
  // (B1) GET LIST + ALL ITEMS
  var list = document.getElementById("demoD");
  var allItems = document.querySelectorAll("#demoD li");

  // (B2) REMOVE FIRST ITEM
  if (first) {
    list.removeChild(allItems[0]);
  }

  // (B3) REMOVE LAST ITEM
  else {
    var last = allItems.length - 1;
    list.removeChild(allItems[last]);
  }
}
</script>
<input type="button" value="Remove First" onclick="delItem(1)"/>
<input type="button" value="Remove Last" onclick="delItem()"/>
  1. First
  2. Second
  3. Third
  4. Forth

Removing items can be a little confusing to some beginners, but the essentials are:

  • Get all the list items – var all = document.querySelectorAll("#LIST li").
  • var all is an HTML collection of all the list items, and it acts like an array. I.E. all[0] refers to the first item, and all[all.length - 1] refers to the last item.
  • So very simply, we just remove the corresponding item from the list itself – document.getElementById("#LIST").removeChild(all[N]).

 

 

USEFUL BITS & LINKS

That’s all for the tutorial, and here is a small section on some extras and links that may be useful to you.

 

INFOGRAPHIC CHEAT SHEET

Add Remove List Items In Javascript (Click To Enlarge)

 

LINKS & REFERENCES

 

THE END

Thank you for reading, and we have come to the end. I hope that it has helped you to better understand, and if you want to share anything with this guide, please feel free to comment below. Good luck and happy coding!

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