HTML | DOM Canvas Object

Last Updated : 15 Jan, 2019

The DOM Canvas Object is used to represent the HTML <Canvas> element. The <canvas> tag is used to draw a graphics in the document using javascript. It is new in HTML5. The canvas element is accessed by getElementById().

Syntax:

accessed by getElementById("id").

Where “id” is the ID assigned to the Canvas tag.

Example-1:

<!DOCTYPE html>
<html>
  
<head>
    <title>canvas Tag</title>
</head>
  
<body>
    <center>
        <h1 style="color:green; Font-size:35px;" >
           GeeksForGeeks
        </h1>
        <h2>DOM Canvas Object</h2>
        
        <!-- canvas Tag starts here -->
        <canvas id="geeks" height="200" width="200" 
                style="border:1px solid green">
        </canvas>
        <!-- canvas Tag ends here -->
        
        <br>
        <br>
        
        <button onclick="myGeeks()">Submit</button>
         
      <script>
            function myGeeks() {
  
                var gfg = document.getElementById("geeks");
                
                var sudo = gfg.getContext("2d");
                sudo.beginPath();
                sudo.arc(100, 100, 90, 0, 2 * Math.PI);
                sudo.stroke();
            }
        </script>
</body>
  
</html>

Output:
Before Clicking On Button:

After Clicking on Button:

Example-2: Canvas Object can be created by using the document.createElement method.

<!DOCTYPE html>
<html>
  
<head>
    <style>
        canvas {
            border: 3px solid black;
        }
    </style>
</head>
  
<body>
    <h1 style = "color: green; font-size:40px;" >
      GeeksForGeeks
    </h1>
    <h2>DOM Canvas Object</h2>
    
    <button onclick="myGeeks()">
      Submit
    </button>
  
    <script>
        function myGeeks() {
            var geeks = document.createElement("CANVAS");
            var gfg = geeks.getContext("2d");
            gfg.fillStyle = "green";
            gfg.fillRect(40, 40, 200, 100);
            document.body.appendChild(geeks);
        }
    </script>
  
</body>
  
</html>