What are these operators, please? -> & =>

suddenshelter

Hi,

I'm trying to advance my PHP skills beyond "Hello World" and keep running across the "=>" and "->" operators, can someone tell me what they are and where to learn more about them?

TIA

rIkLuNd

Here are some of them and what they mean:

&& = AND
|| = OR
< = smaller than...
> = larger than...
>= = larger or equal...
<= = smaller or equal...
== = equals
!= = do not equal

Norman_Graham

Yeah ... try buying a book on PHP, you'll get on a lot faster. However:

=> used, e.g. for specifying the starting index of an array

$myarray=array(1=>"arrayitem1", "arrayitem2" ...);

This is because arrays start automatically at 0, which, for computers, is of course the first 'number'. You might not want this and might want to specify a different starting number. There may be other uses of this symbol.

&& stands for AND, i.e.

if ($name=="" && $e-mail=="") {
echo "Put in your name and e-mail, you moron!";
}

-> is used in OO programming in PHP and, I think, creates an instance of an object or class, but I could be wrong because I'm too thick to understand OO properly, or even at all.

Best o luck

Norman

suddenshelter

Thanks to those who've posted but I'm still a little unclear. From what I'm seeing, "=>" does indeed look like an assignment operator but not necessarily for the first index.

The line:

$arr = array('foo' => 1, 'bar' => 2);

Looks like the functional equivelent of

$arr = array();
$arr['foo'] = 1;
$arr['bar'] = 2;

Is that all "=>" is, shorthand for defining key/value pairs?

What about "->", then? I've seen this operator in some scripts that iteratre through arrays, is "->" another type of assignment operator or some sort of index pointer? How does it work?

edwardsbc

'=>' is the hash assignment operator, particularly useful in arrays:

$array=('First'=>'John','Last'=>'Doe');

It is also used in a few functions dealing with arrays/hash lists:

foreach($array AS $key=>$value) { echo $key,': ',$value; }

'->' is used to select an element in a class:

$myclass->myelement

See the Class section of the PHP Manual