A Guide to Mobile and Web Technology(LAMP)

Archive for the ‘Javascript’ Category

Website Optimization Questions

How do you optimize a website’s assets?
File concatenation, file compression, CDN Hosting, offloading assets, re-organizing and refining code, etc.

What are three ways to reduce page load time?
Reduce image sizes, remove unnecessary widgets, HTTP compression, put CSS at the top and script references at the bottom or in external files, reduce lookups, minimize redirects, caching, etc.

What kind of things must you be wary of when design or developing for multilingual sites?
Another problem with many solutions: setting the default language, using Unicode encoding, using the ‘lang’ attribute, being aware of standard font sizes and text direction, and language word length (may affect layout).

Email Validation using Php and Javascript

This function checks whether the email provided is valid and returns false if not valid.

Php Function for validating email

//$email -> email value to be validated.

function callEmailCheck($email, $strict = false)
$regex = $strict? '/^([.0-9a-z_-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,4})$/i' : '/^([*+!.&#$¦\'\\%\/0-9a-z^_`{}=?~:-]+)@(([0-9a-z-]+\.)+[0-9a-z]{2,4})$/i' ;
if (preg_match($regex, trim($email), $matches))    {
return array($matches[1], $matches[2]);
else {
return false;

This function checks whether the user email entered in the text box is valid or not. Call this function on submit.

Javascript Function for validating email

function callEmailCheck() {
var emailreg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
//useremail is the name of the email text field.
var email = document.getElementById("useremail").value;
if(emailreg.test(email) == true){
return email;
return "";