javascript add css style code example

Example 1: add style javascript

// Bad:
element.setAttribute("style", "background-color: red;");
// Good:
element.style.backgroundColor = "red";

Example 2: javascript modify css

//Pure JavaScript DOM
var el = document.getElementById("elementID");
el.style.css-property = "cssattribute";

//When doing A CSS property that have multiple words, its typed differently
//Instead of spaces or dashes, use camelCase
//Example:
el.style.backgroundColor = "blue";

//Make sure before using jQuery, link the jQuery library to your code
//JavaScript with jQuery
//jQuery can use CSS property to fid=nd an element
$("#elementID").css("css-property", "css-attribute");

//On jQuery, the CSS property is typed like normal CSS property
//Example: 
$("#elementID").css("background-color", "blue");

//If you want multiple property for jQuery, you can stack them on one code
//instead of typing each attribute
//Example: 
$("#elementID").css({"css-property": "css-attribute", "css-property": "css-attribute"});

//you can also make them nice by adding line breaks
//Example: 
$("#elementID").css({
  "css-property": "css-attribute",
  "css-property": "css-attribute"});
//You can add as much CSS property and attribute as you want
//just make sure, always end it with a comma before adding another one
//the last property doesn't need a comma

Example 3: how to change style of an element using javascript

<html>
<body>

<p id="p2">Hello World!</p>

<script>
document.getElementById("p2").style.color = "blue";
</script>

<p>The paragraph above was changed by a script.</p>

</body>
</html>

Example 4: how to give css style in javascript

document.getElementById("myH1").style.color = "red";

Example 5: add css in javascript

document.getElementById("demo").style.display = "none";

Example 6: add css style sheet with javascript

<head>

<script>
function myFunction() {
  var x = document.createElement("LINK");
  x.setAttribute("rel", "stylesheet");
  x.setAttribute("type", "text/css");
  x.setAttribute("href", "styles.css");
  document.head.appendChild(x);
}
myFunction()
</script>

</head>