Need help on PHP GET code - php

Question

Right now I am using this code to grab a variable in my URL:
<?php
$transaction_id = $_GET['transaction_id'];
if($transaction_id == "") {
$transaction_id = 'NA';
}
?>
So far I have only been grabbing that single variable, but now I need to grab a total of 5 variables. Will everything still work properly and operate fast and smoothly if I just copy and paste multiple codes right next to each other like this:
<?php
$transaction_id = $_GET['transaction_id'];
if($transaction_id == "") {
$transaction_id = 'NA';
}
?>
<?php
$transaction_id2 = $_GET['transaction_id2'];
if($transaction_id2 == "") {
$transaction_id2 = 'NA';
}
?>
<?php
$transaction_id3 = $_GET['transaction_id3'];
if($transaction_id3 == "") {
$transaction_id3 = 'NA';
}
?>
Or is there a more efficient way to combine them all into one code?
Thanks for the help.

Answer 1

Make use of isset() construct
<?php
if(!isset($_GET['transaction_id'])) {
$transaction_id = 'NA';
}
if(!isset($_GET['transaction_id2'])) {
$transaction_id2 = 'NA';
}
if(!isset($_GET['transaction_id3'])) {
$transaction_id3 = 'NA';
}
?>

Answer 2

justo to be sure them all are setted and not empty
$na = 'NA';
$transaction_id = (isset($_GET['transaction_id']) && $_GET['transaction_id'] != '') ? $_GET['transaction_id'] : $na ;
$transaction_id2 = (isset($_GET['transaction_id2']) && $_GET['transaction_id2'] != '') ? $_GET['transaction_id2'] : $na ;
...

Answer 3

you could do a for loop
<?php
$transaction_id = array();
for($i=1;$i<6:$i++){
if( $_GET['transaction_id'.$i] == "") {
$transaction_id[] = 'NA'
}else{
$transaction_id[] = $_GET['transaction_id'.$i]
}
}
?>
This will make an array of transaction ids or NA
[0] => NA
[1] => 12345
[2] => 67890
[3] => 23454
[4] => NA
[5] => 55422
I don't know if this is better practice or not, maybe its just a different way.
Hope it helps.
P.S.
you will have to change your first $_GET['transaction_id']; to $_GET['transaction_id1'];