[SOLVED] Newby question: what does "=>" do?

[physaux]

I can't seem to google for it effectively, and "arrows" isn't helping...

 

So could someone tell me what this does? I have seen it in many sample codes. Thanks!!

[Mchl]

It can be used either to declare elements of array

http://www.php.net/manual/en/language.types.array.php

 

Or to declare key and value variables when using foreach

http://www.php.net/manual/en/control-structures.foreach.php

[Daniel0]

[...] and "arrows" isn't helping...

 

It is actually called a T_DOUBLE_ARROW internally in PHP ("T" for token).

[GoneNowBye]

its also a common error for trying to specify greater then or equal to.

 

and somtimes means "implied" in maths, <= means implied by

 

-> is for class objects.

[Daniel0]

its also a common error for trying to specify greater then or equal to.

 

You can always remember that by its name. "Greater than or equal to", so it's first > (greater than) and then = (equal to), i.e. >=.

[GoneNowBye]

Problem there is though, is when you think though it i often thing "equal too or greater then" depending on what i'm solving.... i just know it comes first now

 

 

anyway goodluck

 

 

[GoneNowBye]

it also means "here" on these forms, look at the jump to section just above quick reply

 

sorry last one for now

[physaux]

Hmm interesting thanks for the replies.

It wasnt the "greater than or equal" mistake lol, but thanks for considering all the possibilities

 

Ok, so I am trying to understand it. Here is a sample code where it is used. Could someone clear up for me what exactly is going on?

 

<?php
$employees [] = array(
  'name' => 'Albert',
  'age' => '34',
  'salary' => "$10000"
  );
  $employees [] = array(
  'name' => 'Claud',
  'age' => '20',
  'salary' => "$2000"
  );
  
  $doc = new DOMDocument();
  $doc->formatOutput = true; 
?>

 

I can see that the first "=>" assigns an array, ok thats cool.

But what is the second, "->" part do??

 

Thank you!

[Garethp]

$doc is a class. $doc->formatOutput is the variable "formatOutput" inside the class "$doc"

[ngreenwood6]

Hopefully this will help you physaux: by doing this:

 

$employees [] = array(
  'name' => 'Albert',
  'age' => '34',
  'salary' => "$10000"
);

 

You are creating an associative array. What that means is instead of having an array with 0,1,2 as the index's the index's are what you set here. For example using the array above you could access the fields like this:

 

$employees['name'] //would equal Albert
$employees['age'] //would equal 34
$employees['salary'] //would equal $10000

//without named indexes it would be
$employees[0] //would equal Albert
$employees[1] //would equal 34
$employees[2] //would equal $10000

 

Now for this part:

 

  $doc = new DOMDocument();
  $doc->formatOutput = true; 

 

What you are using there is a class. When you do $doc = new DOMDocument(); you are creating an instance of that class. Then $doc->formatOutput is setting a variable in that class. so for instance the class may look like this:

 

class DOMDocument{
   public formatOutput = false;

   public function helloWorld(){
        echo 'hello world';
   }
}

 

So by doing $doc->formatOutput it is then setting that to true instead. You can also access functions like that as well. So using the example above if you were to do this $doc->helloWorld(); it would output "hello world". All that is doing is making a reference to an object of that class. Hopefully that will clear some stuff up.

[physaux]

Thanks, that really helped to clear stuff up!!  :thumb-up: