php recursive function return only false

Question

function recursiveSearchKeyByVal($array, $needle) {
  //$k = false;
  foreach($array as $key => $val) {
    if( is_array($val) ) {
        $k = array_search($needle, $val);            
        if( $k ) {               
            #var_dump($k);   //<-- string(8) "12345678"      TRUE
            return $k;      //<-- bool(false)               FALSE ?????????
        } else {
           recursiveSearchKeyByVal($val, $needle);
        }
    }
  }
  return false;
}

$array = array( 'a'=>array(...), 'b'=>array( 'b1'=>array( '12345678'=>'abcdefgh' ), ...) );
var_dump( recursiveSearchKeyByVal($array, 'abcdefgh') );

I have this recursive function and I can't make it to return correct value... it only returns false.

you should do "return recursiveSearchKeyByVal($val, $needle);", so the result will go upstairs... otherwise when you call your function, it returns your number, but is ignored, and then continues the foreach, and returns false at the end... — Random
– Random, Commented Jul 17, 2015 at 13:10

ventaquil · Accepted Answer · 2015-07-17 12:54:24Z

1

Heh, you call your function. When you call your function you will called again and again. But when it will return another value than false, it's been deeper than one execution.

You need something like that:

function recursiveSearchKeyByVal($array, $needle) {
  $k = false;
  foreach($array as $key => $val) {
    if( is_array($val) ) {
        $k = array_search($needle, $val);            
        if( $k ) {               
            #var_dump($k);   //<-- string(8) "12345678"      TRUE
            return $k;      //<-- bool(false)               FALSE ?????????
        } else {
           $k = recursiveSearchKeyByVal($val, $needle);
        }
    }
  }
  return $k;
}

answered Jul 17, 2015 at 12:54

ventaquil

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2 Comments

user2039290 Over a year ago

tx, but this example doesn't work.. I get the same result: false

ventaquil Over a year ago

I'm in job and i wrote this fast. Later i will try again :)

KmeCnin · Accepted Answer · 2015-07-17 13:09:12Z

0

This is working and I added the support if the value is at the very first deep of the array, like this you can find anywhere it's.

function recursiveSearchKeyByVal($array, $needle) {
  $k = false;
  foreach($array as $key => $val) {
    if( is_array($val) ) {
        $k = array_search($needle, $val);            
        if( !$k ) {
           $k = recursiveSearchKeyByVal($val, $needle);
        }
    } elseif ($needle == $val) {
        $k = $key;
    }
  }
  return $k;
}

Test here : demo

answered Jul 17, 2015 at 13:09

KmeCnin

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