Implement prepend and append with regular JavaScript

Difficulty Level : Basic
Last Updated : 24 Jun, 2019

The task is to implement prepend() and append() method using regular JavaScript. We’re going to discuss a few methods.
First few methods to know

insertBefore() Method:
This method inserts a node as a child, just before an existing child, which is specified.
Syntax:
```
node.insertBefore(newNode, existingNode)
```
Parameters:
- newNode: This parameter is required. It specifies the node object to insert.
- existingNode: This parameter is required. It specifies the child node to insert the new node before it. If not used, the method will insert the newNode at the end.
Return value:
It returns a node object, which represents the inserted node.
appendChild() Method:
This method appends a node as the last child of a node.
Syntax:
```
node.appendChild(Node)
```
Parameters:
- Node: This parameter is required. It specifies the node object to append.
Return value:
It returns a node object, Which represents the appended node.

Example 1: This example creates a new <p> element and inserts it as the first child of the <div> element using insertBefore() method.

<!DOCTYPE HTML>
<html>
  
<head>
    <title>
        JavaScript 
      | implement prepend and 
      append with regular JavaScript.
    </title>
</head>
  
<body style="text-align:center;" id="body">
    <h1 style="color:green;">  
            GeeksForGeeks  
        </h1>
    <p id="GFG_UP" 
       style="font-size: 15px; font-weight: bold;">
    </p>
    <div id="parent">
        <p class="child">child_1</p>
        <p class="child">child_2</p>
        <p class="child">child_3</p>
    </div>
    <button onclick="gfg_Run()">
        Click here
    </button>
    <p id="GFG_DOWN"
       style="color:green; 
              font-size: 20px;
              font-weight: bold;">
    </p>
    <script>
        var el_up = document.getElementById("GFG_UP");
        var el_down = document.getElementById("GFG_DOWN");
        var today = 'Click on button implement prepend method';
        el_up.innerHTML = today;
  
        function gfg_Run() {
            var par = document.getElementById("parent");
            var child = document.getElementsByClassName("child");
            var newEl = document.createElement("p");
            newEl.innerHTML = "child_0";
            par.insertBefore(newEl, child[0]);
            el_down.innerHTML = "New element inserted";
        }
    </script>
</body>
  
</html>

Output:

Before clicking on the button:
After clicking on the button:

Example 2: This example creates a new <p> element and inserts it as the last child of the <div> element using appendChild() method.

<!DOCTYPE HTML>
<html>
  
<head>
    <title>
        JavaScript 
      | implement prepend and append 
      with regular JavaScript.
    </title>
</head>
  
<body style="text-align:center;" id="body">
    <h1 style="color:green;">  
            GeeksForGeeks  
        </h1>
    <p id="GFG_UP"
       style="font-size: 15px;
              font-weight: bold;">
    </p>
    <div id="parent">
        <p class="child">child_1</p>
        <p class="child">child_2</p>
        <p class="child">child_3</p>
    </div>
    <button onclick="gfg_Run()">
        Click here
    </button>
    <p id="GFG_DOWN"
       style="color:green; 
              font-size: 20px;
              font-weight: bold;">
    </p>
    <script>
        var el_up = document.getElementById("GFG_UP");
        var el_down = document.getElementById("GFG_DOWN");
        var today = 'Click on button implement append method';
        el_up.innerHTML = today;
  
        function gfg_Run() {
            var par = document.getElementById("parent");
            var newEl = document.createElement("p");
            newEl.innerHTML = "child_4";
            par.appendChild(newEl);
            el_down.innerHTML = "New element inserted";
        }
    </script>
</body>
  
</html>

Output:

Before clicking on the button:
After clicking on the button:

My Personal Notes

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