For Each structure is a loop structure used for arrays

    foreach (array_expression as $value)
      statement

    foreach (array_expression as $key => $value)
     statement

In Syntax1 the array is given by the "array expression" and each value of the elements is assigned to "$value". Syntax2 is also similar, but only difference is that current elements key is assigned to "$value".

     <?php
     $arr["One"]= "1";
     $arr["Two"]= "2";
     $arr["Three"]= "3";
     foreach ($arr as $value => $key) 
     {
      echo "The value $value, has the key $key </br>";
     }
     ?>

    The value One, has the key 1
    The value Two, has the key 2
    The value Three, has the key 3 

In the above example the $value is preceded by "&",it means that the array is referenced, this is to make changes to the array elements, instead of having the copy of a array. Usually reference of a $value and the last array element remain even after the foreach loop,so to remove that we use unset().