HTML DOM Window top( ) Property
The Window top() property is used to return the topmost browser window of a current window. It is a read-only property and it returns a reference to the topmost window in the window hierarchy.
Syntax:
window.top
Return Value: It returns the reference of the topmost window in the window hierarchy.
Below program illustrates the Window top() property :
Checking whether the window is the topmost browser window or not.
html
<!DOCTYPE> < html > < head > < title > Window top() property in HTML </ title > < style > h1 { color: green; } h2 { font-family: Impact; } body { text-align: center; } </ style > </ head > < body > < h1 >w3wiki</ h1 > < h2 >Window top() Property</ h2 > < p > For checking whether the window is the topmost window or not, double click the "Check Top Window" button: </ p > < button ondblclick = "Window()" > Check Top Window </ button > < p id = "MyWindow" ></ p > < script > function Window() { if (window.top = window.self) { document.getElementById("MyWindow").innerHTML = "This window is the topmost window."; } else { document.getElementById("demo").innerHTML = "This window is not the topmost window."; } } </ script > </ body > </ html > |
Output:
After clicking the button
Supported Browsers: The browser supported by Window top( ) Property are listed below:
- Google Chrome 1 and above
- Edge 12 and above
- Internet Explorer 4 and above
- Firefox 1 and above
- Opera 12.1 and above
- Safari 3 and above