HTML | DOM KeyboardEvent

Difficulty Level : Basic
Last Updated : 22 Apr, 2019

It refers to the events which occur when a key is pressed on the keyboard.

Syntax:

<input type=”text” onkeypress/onkeydown/onkeyup=”function()/event”>

Events:The following events occur on pressing a key-

onkeydown
onkeypress
onkeyup

Properties:

altKey: It returns if alt key was pressed or not.
charCode: It returns unicode character of the key.
code: It returns the code of the entered key.
ctrlKey: It returns if ctrl key was pressed or not.
getModifierState(): It returns true if the specified key is activated.
isComposing: It returns whether the event is composing or not.
key: It returns the key value.
keyCode: It returns unicode character of the onkeypress or onkey doen event.
location: It returns the location of the key on the keyboard.
metaKey: It returns if meta key was pressed or not.
repeat: It returns if a key is repeatedly holding on.
shiftKey: It returns if shift key was pressed or not.
which: It returns the unicode character of event type.

Return Value: It returns events which occur when a given key is pressed from the keyboard.

Example-1: Showing onkeypress event.

<!DOCTYPE html>
<html>
  
<body>
  
    <h1>
      <center>Geeks for Geeks </center> 
  </h1>
  
    <p>Type something in the box:</p>
  
    <input type="text" onkeypress="key()">
  
    <script>
        function key() {
            alert("New Key Inserted");
        }
    </script>
  
</body>
  
</html>

Output:
Before Pressing a key:

After Pressing a key:

Example-2: Showing onkeydown event.

<!DOCTYPE html>
<html>
  
<body>
  
    <h1>
      <center>Geeks for Geeks </center>
  </h1>
  
    <p>Type something in the box:</p>
  
    <input type="text" onkeydown="key()">
  
    <script>
        function key() {
            alert("New Key Inserted");
        }
    </script>
  
</body>
  
</html>

Output:
Before Pressing a key:

After Pressing a key:

Example-3: To check if the pressed key is Alt or not.

<!DOCTYPE html>
<html>
  
<body>
  
    <h1>
      <center>Geeks for Geeks </center> 
  </h1>
  
    <p>Type something in the box to 
      check if Alt key is pressed or not:</p>
  
    <input type="text" onkeydown="isKeyPressed(event)">
  
    <p id="gfg"></p>
  
    <script>
        function isKeyPressed(event) {
            var x = document.getElementById("gfg");
            if (event.altKey) {
                x.innerHTML = "ALT Key Pressed";
            } else {
                x.innerHTML = "ALT Key Not Pressed";
            }
        }
    </script>
  
</body>
  
</html>

Output:
Before Pressing a key:

After Pressing a key:

Example-4: To find out the pressed key from the keyboard.

<!DOCTYPE html>
<html>
  
<body>
  
    <h1>
      <center>Geeks for Geeks </center> 
  </h1>
  
    <p>Type something in the box
      to know the entered key:</p>
  
    <input type="text" 
           size="40" 
           onkeydown="myFunction(event)">
  
    <p id="gfg"></p>
  
    <script>
        function myFunction(event) {
            var x = event.key;
            
            document.getElementById(
              "gfg").innerHTML =
              "Entered Key is: " + x;
        }
    </script>
  
</body>
  
</html>