Arrays: array_shift($arr) or $arr[0]?

Question

Which one would you use?

Basically I only want to get the 1st element from a array, that\'s it.

Answer 1

If you have an associative Array you can also use reset($arr): It returns the first Element (doesn't remove), and sets the array pointer to this element.

But the fastest way is $arr[0].

Answer 2

Do you want to modify the arr array also? array_shift removes the first element of the array and returns it, thus the array has changed. $arr[0] merely gives you the first element.

I would use $arr[0] unless I explicitly wanted to modify the array. You may add code later to use the arr array and forget that it was modified.

Answer 3

$arr[0] only works if the array as numerical keys.

array_shift removes the element from the array and it modifies the array itself.

If you are not sure what the first key is , and you do not want to remove it from the array, you could use:

<?php
foreach($arr $k=>$v){
   $value = $v;
   break;
}

or even better:

<?php
reset($arr);
$value = current($arr);

Answer 4

If you don't want to change the array in question, use $arr[0] (which merely gets the first element), otherwise if you want to remove the first element of $arr from $arr, use array_shift($arr).

For example:

$arr=array(3,-6,2);
$foo=$arr[0]; //$foo==3 and $arr==array(3,-6,2).
$bar=array_shift($arr); //$bar==3 and $arr==array(-6,2).

ETA: As others have pointed out, be sure that your array isn't an associative array (ie the keys are 0,1,...,(sizeof($arr)-1)), otherwise this probably won't work.

Answer 5

Well, they do different things.

• array_shift($arr) takes the first element out of the array, and gives it to you.

• $arr[0] just gives it to you... if the array has numeric keys.

An alternative that works for associative arrays too is reset($arr). This does move the array's internal pointer, but unless you're using those functions this is unlikely to affect you.