Understanding PHP syntax

[cleanair4me]

I am not familiar with PHP terminology and trying to understand the below:

if(isset($_GET['myWord']) && isset($_GET['letters']))
isset means has the value been defined and is not null?


$letters = preg_replace("/[^a-z9 ]/si","",$letters);
preg_replace is a pattern match method that has 3 arguments where first is the reg expression match, second is the replacement and third argument is the variable?

 

[johnwm]

To get started with PHP try:

http://www.w3schools.com/php/default.asp

For continuing everyday use try:

http://www.php.net/docs.php

___________________________________________________________
If you want the best response to a question, please check out FAQ222-2244 first.
'If we're supposed to work in Hex, why have we only got A fingers?'
Drive a Steam Roller
Steam Engine Prints

 

[bluntbill]

you're correct.

isset checks if the var exists, to avoid showing a notice that some var is not defined.

the third argument of preg_replace is the text where you want to perform the replacement.

 

[jpadie]

isset will also report false if the variable exists but is set to null. so be careful - it's not always the best test to use.

 

[cleanair4me]

Thanks