數組鍵值相同，但將值添加到vlaues中？

Question

This my array.... 

     Array 
     (
      [a1]=>'k' 
      [a2]=>'a' 
      [a3]=>'w' 
      [a4]=>'z' 

     } 

i want  Array 
     (
      [a1]=>'k,a' 
      [a3]=>'w' 
      [a4]=>'z' 

     } 

Answer 1

$arr = ...; 
unset($arr['Â 7'], $arr['Â 11']); 
$arr[6] = 7; 
$arr[10] = 11;