code-boxx/0-JS-LI.MD

## 0-JS-LI.MD

      
    Raw
  

              0-JS-LI.MD
            
          
    JAVASCRIPT ADD REMOVE HTML LIST ITEMS

https://code-boxx.com/add-remove-list-items-javascript/
LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## 1-create-element.html
<!DOCTYPE html>
<html>
  <head>
    <title>Add Remove List Items</title>
  </head>
  <body>
    <!-- (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()">
  </body>
</html>

## 2-insert-position.html
<!DOCTYPE html>
<html>
  <head>
    <title>Add Remove List Items</title>
  </head>
  <body>
    <!-- (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()">
  </body>
</html>

## 3-insert-html.html
<!DOCTYPE html>
<html>
  <head>
    <title>Add Remove List Items</title>
  </head>
  <body>
    <!-- (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()">
  </body>
</html>

## 4-remove-item.html
<!DOCTYPE html>
<html>
  <head>
    <title>Add Remove List Items</title>
  </head>
  <body>
    <!-- (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()">
  </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>Add Remove List Items</title>
	</head>
	<body>
	<!-- (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()">
	</body>
	</html>