add styling using js code example

Example 1: add style javascript

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

Example 2: adding styling to element using javascript

var elem = document.querySelector('#some-element');

// Set color to purple
elem.style.color = 'purple';

// Set the background color to a light gray
elem.style.backgroundColor = '#e5e5e5';

// Set the height to 150px
elem.style.height = '150px';

Example 3: add css in javascript

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