How to make URL change content of a website? [duplicate] - php

Question

This question already has answers here:
Correct syntax for hyperlink URL with PHP $_GET
(3 answers)
Closed 7 years ago.
Hope you'll be able to help me, as I searched all around Google with various keywords and couldn't find anything relevant to me, or I just don't know what this thing I'm curios about is called.
I have a website, which I want to be personalized, according to the URL string.
So I'd link to send my friend a link like http://example.com/index.php?name=Joanna and it would change the beggining of my page to "Hi Joanna!". I just want it to be simple as that and integrate it into PHP or HTML (which is easier), but don't know how to achieve that.
Any help would be appreciated :)
P.S. - Keep the "How you don't know that?" remarks away , I'm new at this and am still learning.

Answer 1

See HTTP GET Variables
If your URL is
www.example.com/index.php?name=Joanna
it means that $_GET["name"] is "Joanna".
So in PHP, you can output:
<?php echo "Hi ".$_GET["name"]."!"; ?>
and it will output, in this case:
Hi Joanna!
You can also check that the variable exists and isn't empty by doing one of the following:
isset($_GET["name"]) //will return true even if $_GET==""
!empty($_GET["name"])
$_GET["name"]!=""
So you can change your PHP output to:
if(!empty($_GET["name"])){
$name = $_GET["name"];
} else {
$name = "guest";
}
echo "Hi, ".$name."!";
which will output "guest" if $_GET["name"] is empty.
Shorter version of the above:
echo "Hi, ".(empty($_GET["name"]) ? "guest" : $_GET["name"])."!";