David Thomas Baker » PHP » PHP Stuff

When playing around and helping some guys at work learn more PHP I thought I would keep a record of some things we discussed.

echo " 123"; will print out a capital "S" - the octec value for S is 123.

when posting files from a form, use <form action="foo.php" method="post" enctype="multipart/form-data"> without the enctype the file will not be sent to the server

when storing data in sessions: if there is a session key called $_SESSION['products'] and you use $products somewhere in your scripts for a different reason eg: $products=query("SELECT * FROM...); on some PHP configurations $products and $_SESSION['products'] will be the same, so be careful with session key names. you could end up inadvertently messing with session values

if you have an input element <input type="checkbox" name="foo[123]" value="Bar"> PHP will convert foo[123] into an array for you automatically. You can access this like: $foo = $_POST['foo']; echo $foo["123"]; // this prints Bar

after submitting a form (lets say a sign up form) it is always best to redirect the user to a separate "thank you" page instead of simply displaying a thankyou message at the end of the sign up script. this means if a user refreshes the "thank you" page, it will not sign them up again / throw a nasty re-post warning message in the browser.

more to come ...

PHP:

<?=($foo)?$bar:$moo;?>

same as:

<? if($foo) echo $bar; else echo $moo; ?>

<input type="checkbox" name="box[a]" value=yes>
<input type="checkbox" name="box[b]" value=yes>
<input type="checkbox" name="box[c]" value=yes>
<input type="checkbox" name="box[d]" value=yes>
print_r($_REQUEST);

json_encode()

while($v<20){
  ?> <tr bgcolor="<?=($v++%2)?'red':'green';?>"><td>fasdf</td></tr> <?
}

preg_match("/^(http:\/\/info@)?([^\/]+)/i","http://info@abc.com", $data);
echo $data[2]; 

HTML:

whats a <th>

Javascript:

var moo = {
        foo: function(){
                var b = this.a--;
                alert(--b)
        },
        a: 4
}
moo.a=3;
moo.foo();

// alerts 2

var moo = {a : "string", b: 4, c: function(){ alert('moo'); } };