Multidimensional Array to String

Saving the imploded inner arrays to an array. Then imploding those.

(written in the spirit of your original implementation)

function convert_multi_array($arrays)
{
    $imploded = array();
    foreach($arrays as $array) {
        $imploded[] = implode('~', $array);
    }
    return implode("&", $imploded);
}

Look at my version. It implodes any dimension:

function implode_all($glue, $arr){            
    for ($i=0; $i<count($arr); $i++) {
        if (@is_array($arr[$i])) 
            $arr[$i] = implode_all ($glue, $arr[$i]);
    }            
    return implode($glue, $arr);
}

Here is the example:

echo implode_all(',', 
array(
1,
2,
array('31','32'),
array('4'),
array(
  array(511,512), 
  array(521,522,523,524),
  53))
);

Will print:

1,2,31,32,4,511,512,521,522,523,524,53

I tried a bunch of these, but non of them ticked all the boxes for me. The one that came the closes was Jeff_Alieffsons.

Here is an adjusted version, where you can chuck whatever multidimensional array into it, and then it'll return a string.

function implode_all( $glue, $arr ){
  if( is_array( $arr ) ){

    foreach( $arr as $key => &$value ){

      if( @is_array( $value ) ){
        $arr[ $key ] = implode_all( $glue, $value );
      }
    }

    return implode( $glue, $arr );
  }

  // Not array
  return $arr;
}

You are overwriting $array, which contains the original array. But in a foreach a copy of $array is being worked on, so you are basically just assigning a new variable.

What you should do is iterate through the child arrays and "convert" them to strings, then implode the result.

function convert_multi_array($array) {
  $out = implode("&",array_map(function($a) {return implode("~",$a);},$array));
  print_r($out);
}