The MouseEvent button property is used to define the left or right-click events. When the mouse button is clicked then it returns an integer value which describes the left, right, or middle mouse button. Syntax:
event.button
Return Value: This event returns an integer value on mouse click events are:
- 0: It indicates the left mouse button.
- 1: It indicates the middle mouse button.
- 2: It indicates the right mouse button.
The onmousedown event: This event occurs when a user presses a mouse button over an element.
Example 1:
<h1 style="color:green">
GeeksforGeeks
</h1>
<h2>Mouse click event</h2>
<button onclick="click(event)">Click me</button>
<p id="demo"></p>
<script>
document.onmousedown = click
// click function called
function click(event) {
// Condition to disable left click
if (event.button == 0) {
document.getElementById("demo").innerHTML= "Left click not allowed"
}
}
</script>
Output:

Example 2:
<h1 style="color:green">
GeeksforGeeks
</h1>
<h2>Mouse click event</h2>
<button onclick="click(event)">Click me</button>
<p id="demo"></p>
<script>
document.onmousedown = click
// click function called
function click(event) {
// Condition to disable left click
if (event.button == 2) {
document.getElementById("demo")
.innerHTML = "Right click not allowed";
}
}
</script>
Output:

We have a complete list of Mouse Events, to check those please go through this HTML DOM MouseEvent article