why key($myArray) does not return key inside " For Each " Loop ??

[lostnucleus]

$data = array('cat','bat','rat','net');

foreach($data as $value)
{
echo key($data);
}

 

The output of above code is "111" ???

why it is not 0 , 1 ,2 ,3 ??

 

Thx in Advance.

 

 

[roopurt18]

Well that's interesting.

 

But why not just use:

<?php
foreach( $data as $key => $value ) {
echo $key;
}

[ignace]

Well that's interesting.

 

No, actually not. key() does not advance the internal array pointer. And the 111 is due to his code, not the above example. Which outputs 000

 

$data = array('cat','bat','rat','net');
echo key($data), '<br/>';

foreach($data as $key => $value)
{
echo 'key(): ', key($data), ' $key: ', $key, '<br/>';
}

 

Outputs:

 

0<br/>
key(): 1 $key: 0<br/>
key(): 1 $key: 1<br/>
key(): 1 $key: 2<br/>
key(): 1 $key: 3<br/>

 

foreach() advances the array pointer by 1?

[Kryptix]

<?php
$data = array("cat", "bat", "rat", "net");

foreach($data as $value) {
	echo $value;
}
?>

 

Output: catbatratnet

[ignace]

On each loop, the value of the current element is assigned to $value and the internal array pointer is advanced by one...

 

...When foreach first starts executing, the internal array pointer is automatically reset to the first element of the array...

 

...foreach operates on a copy of the specified array and not the array itself

 

Then why is the original array internal pointer advanced by one?

[lostnucleus]

On each loop, the value of the current element is assigned to $value and the internal array pointer is advanced by one...

 

...When foreach first starts executing, the internal array pointer is automatically reset to the first element of the array...

 

...foreach operates on a copy of the specified array and not the array itself

 

Then why is the original array internal pointer advanced by one?

 

That Q is killing me , why this is happening ???

 

 

[roopurt18]

Possibly a bug or constraint in how arrays (or foreach) are implemented?

[lostnucleus]

Possibly a bug or constraint in how arrays (or foreach) are implemented?

hmm ... well then sm1 needs to report this bug on php.net .....

[PFMaBiSmAd]

The discrete array functions that modify or access an array pointer - end(), key(), each(), prev(), reset(), next(), ... cannot be used inside of a foreach() loop to access the same array that is being iterated over. There is no need to do so or you should not be using a foreach() loop in the first place.