从PHP迭代器返回多个项目

Question

Is there a way with a PHP Iterator object to sometimes return multiple items from a single item?

For example, suppose I have an array:

$a = ['1','2','3','double 6','4'];

and I want to have an Iterator object that takes this and produces the following items:

• 1
• 2
• 3
• 6
• 6
• 4

Answer 1

You have to make of definite array for such string like

"double"=>2,"triple"=>3,"quadruple"=>4, "quintuple"=>5

<?php
  $str = ["double"=>2,"triple"=>3,"quadruple"=>4, "quintuple"=>5];
  $a = ['1','2','3','double 6','4'];
  foreach($a as $key=>$val){
    $val = explode(" ",$val);
    if(count($val) > 1){
      $a[$key] = $val[1];
      for($i=1;$i<$str[$val[0]];$i++){
        $a[] = $val[1];
      }
    }
  }
  sort($a);
  print_r($a);
?>

Live Demo