Form Validation

[chronister]

I have run across this many times now and I wanted to get your opinions.

 

I have a login form (though this persists with all forms). On my login.php page, if I use this code

 

if(isset($_POST['username']))
{
'do whatever here';
}

 

Once the form is submitted this always evaluates to true even if the field was left empty.

 

I have used this

 

if($_POST['username'] !=='')
{
'do whatever here'
}

 

A single space in the field will make this evaluate to true thus username field is no longer blank, but nothing was entered.

 

empty() gives the same results as !==''.

 

The only other way I can think of to ensure that something was entered is to use strlen() and make sure the fields are above a certain length. Does this sound plausible to anyone else, or is there a better way?

 

Thanks,

 

Nate

 

 

 

 

[LazyJones]

strlen is a sufficient way of checking the length.

 

To get rid of empty strings (like spaces or tabs), use trim