Finding a specific key in an php array

Question

I have some troubles finding the right key in an array:

when I have an array: $haystack

$haystack = array(0 => 'apple', 
                  1 => 'apple', 
                  2 => 'pear', 
                  3 => 'apple', 
                  4 => 'banana');

and is use the function array_search

$key = array_search('apple', $haystack);

the function wil set the $key value to '0' ( $key = 0 )

I need to find the key of the fourth item in the array (3) which is also apple... Does anyone know a function that searches the array from a given index and returns a value?

for example something like:

array_search_start($needle, $haystack, $startPosition);

dfsq · Accepted Answer · 2012-01-31 16:51:59Z

4

Use array_keys with the second parameter to specify value to search keys for.

$keys = array_keys($haystack, 'apple');

So $keys will contain array of found keys corresponding to search value (apple):

Array
(
    [0] => 0
    [1] => 1
    [2] => 3
)

Now you can get the last one, or the first, etc. If you need the last:

$key = end($keys);

edited Jan 31, 2012 at 16:51

answered Jan 31, 2012 at 16:37

dfsq

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1 Comment

Ben D Over a year ago

This will only give you the last key... OP asked for an offset from a specified index, not necessarily the last one. You should modify to get first key >= $startPostion

Mikhail · Accepted Answer · 2012-01-31 16:35:31Z

0

This should work:

<?php
function array_search_start($needle, $haystack, $start) {
  for ($i = $start; $i < length($haystack); $i++)
    if ($haystack[$i] == $needle) return $i;
  return FALSE; // You'll need === operator to distinguish between False and 0
}
?>

Good luck!

answered Jan 31, 2012 at 16:35

Mikhail

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Comments

Ben D · Accepted Answer · 2012-01-31 16:37:45Z

0

You can also use array_slice to do this more simply than looping:

<?php
$key = array_search($needle, array_slice($haystack, $startPosition,-1,true));
?>

This syntax requires PHP>=5.0.2, as we need to preserve the keys (hence the -1 (no length limit) and true which keeps the original keys)

answered Jan 31, 2012 at 16:37

Ben D

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Comments

DJ Burb · Accepted Answer · 2012-01-31 16:41:11Z

0

Don't know much about PHP but, couldn't you just include an offset as the start position?

int strpos ( string $haystack , mixed $needle [, int $offset = 0 ] )

So, in your case you would do

$key = array_search('apple', $haystack, 2);

answered Jan 31, 2012 at 16:41

DJ Burb

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Comments

Sabari · Accepted Answer · 2012-01-31 16:41:14Z

0

You can use array_keys to get all keys with values apple

$keys = array_keys($haystack, 'apple');

if you need it to write as a function then you can do:

$searchValue = 'apple';
$keys = searchKeys($haystack, $searchValue);
function searchKeys($haystack,$searchValue) {
     $keys = array_keys($haystack, $searchValue);
     return $keys;
}

Hope this helps you :)

answered Jan 31, 2012 at 16:41

Sabari

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Comments

chenio · Accepted Answer · 2012-01-31 16:50:19Z

0

<?

$array = array("one"=>'paul',"two"=>'lady');
print_r(array_values($array));

?>

answered Jan 31, 2012 at 16:50

chenio

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Comments

Ali Demirci · Accepted Answer · 2012-01-31 16:54:54Z

0

$haystack = array(0 => 'apple', 
                  1 => 'apple', 
                  2 => 'pear', 
                  3 => 'apple', 
                  4 => 'banana');
$find = 'apple';
foreach ($haystack as $k=>$v) {
    if($find == $v) {
            echo 'found! key is '.$k.'<br />';
            }
}

answered Jan 31, 2012 at 16:54

Ali Demirci

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Comments

Sam Arul Raj T · Accepted Answer · 2012-02-03 20:12:35Z

0

This will be so easy to use

$haystack = array(0 => 'apple', 
                  1 => 'apple', 
                  2 => 'pear', 
                  3 => 'apple', 
                  4 => 'banana');

$keys = array_keys($haystack,'apple');
foreach($keys as $k):
    $searchK[] = $haystack[$k];
endforeach;

print_r($searchK);

answered Feb 3, 2012 at 20:12

Sam Arul Raj T

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