[SOLVED] how to use a method in array_walk

[jaikar]

hi there,

 

i am trying to use a method in array_walk.. something like this

 

class test {

  function one() {

      $t = array('one', 'two');

      array_walk($t, '$this0>converttolower');

  }

 

  function convertolower($value, $key) {

      $t[$key] = strtolower($value);

  }

}

 

the above is not working, how to make something like this work.

 

thankyou.

[papaface]

  array_walk($t, '$this0>converttolower');

should be

  array_walk($t, $this->converttolower);

I think

[ignace]

array_walk($t, array(&$this, 'converttolower'));

[.josh]

or just cut the middleman out and use array_map

 

class test {
   function one() {
      $t = array('one', 'two');
      $t = array_map('strtolower',$t);
   }

}

 

[jaikar]

Awesome Crayon !.. it worked like charm for my purpose...

 

ignace, your idea did not worked.. i dont know why. it said invalid argument.

 

but still, to my question... there is no way to use a method as argument in array_walk ?

 

thankyou!

[.josh]

It is possible, but you have to pass it as the static method version not with the $this shortcut, because it won't parse the $this.  Also, you had a couple other things wrong.  First, your method is called converttolower but you were trying to array_walk convertolower (missing a t in there).  2nd, you weren't doing it right in your converttolower method.  In order to change it, you have to pass the value by reference, and then assign the alteration to the passed value.  You cannot array_walk and make changes to the original array the way you were doing ($t[blah]) as that will cause array_walk to go AWOL.  So here's how it would look:

 

class test {
   function one() {
      $t = array('ONE', 'tWo');
      array_walk($t, 'test::converttolower');
   }

   function converttolower(&$value, $key) {
     $value = strtolower($value);
   }
}

[Daniel0]

OP, see: http://php.net/manual/en/language.pseudo-types.php#language.types.callback

 

array_walk($t, array(&$this, 'converttolower'));

 

Objects are passed by reference by default.

[jaikar]

Crayon, ... Awesome !.. and a fantastic explanation .. .. respect !!.... thankyou very much !!. additinally, you also explained the value by referance concept, which would be next question for i did not know why & was used !... actualy, i studied this long back but forgot and never used this in anycodes. . thankyou !..

 

Dan, !.. happy to see you again !! ... thankyou for the doc link .. it really expains a lot, i did not got this link in google, but after seing the link, i noticed how to pull up help for arguments and callbacks.. php doc is awesome as always!!

 

i have one more clarification,  i have a situation where i have to compare values of 2 arrays.. like

 

$arr1 = array('one', 'two');

 

$arr2 = array('one', 'three', 'four');

 

comparing like, if $arr2 have atlest one value in arr1, then some code will execute. question is .. is it possble to do this without using a loop ? is there a funciton for this in php ?

 

thankyou !

 

 

[Daniel0]

You could do like:

if (count(array_insersect($arr1, $arr2))) {
// they share at least one element
}
else {
// they don't
}

[jaikar]

 

Dan, YOU ARE THE MANNNNNNNNNNNN !!.. i almost thought there is no function for this task... just tested and works perfect !!! ... i am speechless now ... never thought array_intersect is used for this.. it just says "Computes the intersection of arrays". i was not able to understand that. i am really surpriced for your knowledge in php !! ...

 

thankyou so much

[.josh]

well that's kind of what intersection means...an intersection is where something meets.  A more common use of that word is with roads and streets.  When they cross, that's an intersection.