HTML id attribute specifies unique element within HTML document. Keep in mind that, the same id attribute of an HTML element can not assign to other HTML elements.
Note HTML id attribute specifies a unique HTML element means no other HTML element can put the same id.
<h2 id="main_heading">This is HTML heading tag</h2>
Source Code
<h2 id="main_heading">This is HTML heading tag</h2>
Note:Here,HTML element <h2> having unique id(main_heading). That will be unique inside the HTML document.
To write a cascade style sheet for the specific Id of the HTML element, write a hash character followed by an id name. Then define the CSS rule inside curly bracket{}.
#main_heading {
background-color:orange;
color: black;
padding: 40px;
text-align: center;
}
Source Code
#main_heading {
background-color: lightblue;
color: black;
padding: 40px;
text-align: center;
}
Note: The CSS rule has been written with respect to the unique id of the HTML element is only applicable to a single HTML element.
Source Code
<script>
function displayResult() {
document.getElementById("main_heading").innerHTML = "You can see the result right now.";
}
</script>
Note:Javascript is used getElementById() method to fetch HTML element having a unique id.
Source Code
#main_heading{
background-color: violet;
padding: 20px;
text-align: center;
color: black;
}
.flower{
background-color: orange;
padding: 12px;
color: black;
}
Note:An HTML element has a unique id means this id can not assign to other HTML elements while a class to be assigned more than one HTML element.
