Example:
sessionStorage.setItem("key", "value");
Example:
if (sessionStorage.clickcount)
{
sessionStorage.clickcount=Number(sessionStorage.clickcount)+1;
}
else
{
sessionStorage.clickcount=1;
}
document.getElementById("result").innerHTML="You have clicked the button " + sessionStorage.clickcount + " time(s) in this session.";

Explanation/Reference:
The innerHTML property sets or returns the inner HTML of an element.
Example:
document.getElementById('myAnchor').innerHTML="Contoso";
The title property sets or returns the element's advisory title.
Example:
var x=document.getElementsByTagName('body')[0];
document.write("Body title: " + x.title);

Explanation
Note:
* In JavaScript this always refers to the "owner" of the function we're executing, or rather, to the object that a function is a method of.
* If you assign a value to variable that has not yet been declared, the variable will automatically be declared as a GLOBAL variable.
This statement:
carname="Volvo";
Will declare the variable carname as a global variable , even if it is executed inside a function.

Note:
Cookies are small, usually randomly encoded, text files that help your browser navigate through a particular website. The cookie file is generated by the site you're browsing and is accepted and processed by your computer's browser software. The cookie file is stored in your browser's folder or subfolder.