HTML 5 web storage

Storing data on the client

HTML5 provides two new methods of storing data on the client:

localStorage - data storage without time limit

sessionStorage - Before data storage for a session

, these were all done by cookies. But cookies are not suitable for storing large amounts of data because they are passed with each request to the server, which makes cookies slow and inefficient.

In HTML5, data is not passed by every server request, but data is only used when requested. It makes it possible to store large amounts of data without affecting website performance.

For different websites, data is stored in different areas, and a website can only access its own data.

HTML5 uses JavaScript to store and access data.

localStorage method

The data stored by the localStorage method has no time limit. The data is still available after the next day, week or year.

How to create and access localStorage:

Example

<script type="text/javascript">localStorage.lastname="Smith";document.write(localStorage.lastname);
</script>

The following example counts the number of times a user visits a page:

Example

<script type="text/javascript">
if (localStorage.pagecount)
  {
  localStorage.pagecount=Number(localStorage.pagecount) +1;
  }
else
  {  localStorage.pagecount=1;
  }
document.write("Visits "+ localStorage.pagecount + " time(s).");
</script>

sessionStorage method

The sessionStorage method stores data for a session. The data is deleted when the user closes the browser window.

How to create and access a sessionStorage:

Example

<script type="text/javascript"> sessionStorage.lastname="Smith"; document.write(sessionStorage.lastname); </script>

The following example counts the number of times a user visits a page in the current session:

Example

<script type="text/javascript">
if (sessionStorage.pagecount)
  {
  sessionStorage.pagecount=Number(sessionStorage.pagecount) +1;
  }
else
  {  sessionStorage.pagecount=1;
  }
document.write("Visits "+sessionStorage.pagecount+" time(s) this session.");
</script>

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