The task is to find whether an element exists in the visible DOM or not. For that purpose, there is a number of methods used but we’re going to look at few of them.
Example-1: In this example, the element is searched by document.getElementById(‘Id’) and !! is used before selector to get the boolean result.
<!DOCTYPE HTML>
<html>
<head>
<title>
JavaScript
| Check if element exists in the visible DOM.
</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;">
Check if an Element exists in visible DOM
</p>
<button onclick="gfg_Run()">
check
</button>
<p id="GFG_DOWN"
style="color:green;
font-size: 23px;
font-weight: bold;">
</p>
<script>
var el_down =
document.getElementById("GFG_DOWN");
var id = 'GFG_UP';
function gfg_Run() {
var element =
!!document.getElementById(id);
var ans = '';
if (element) {
ans = "Element of id = '" + id +
"' exists in visible DOM.";
} else {
ans = "Element of id = '" + id +
"' not exists in visible DOM.";
}
el_down.innerHTML = ans;
}
</script>
</body>
</html>
|
Output:
- Before clicking on the button:
- After clicking on the button:
Example-2: In this example, the element is searched by document.getElementsByClassName(‘className’) and length property is used to check whether variable contains results or not.
<!DOCTYPE HTML>
<html>
<head>
<title>
JavaScript
| Check if element exists in the visible DOM.
</title>
</head>
<body style="text-align:center;"
id="body">
<h1 style="color:green;">
GeeksForGeeks
</h1>
<p id="GFG_UP"
class="p"
style="font-size: 15px;
font-weight: bold;">
Check if an Element exists in visible DOM
</p>
<button onclick="gfg_Run()">
check
</button>
<p id="GFG_DOWN"
class="p"
style="color:green;
font-size: 23px;
font-weight: bold;">
</p>
<script>
var el_down =
document.getElementById("GFG_DOWN");
var className = 'p';
function gfg_Run() {
var element =
document.getElementsByClassName(className);
var ans = '';
if (element.length > 0) {
ans = "Element of className = '" + className +
"' exists in visible DOM.";
} else {
ans = "Element of className = '" + className +
"' not exists in visible DOM.";
}
el_down.innerHTML = ans;
}
</script>
</body>
</html>
|
Output:
- Before clicking on the button:
- After clicking on the button:
