php获取英文姓名首字母的方法

<?php 
function initials($name){ 
  $nword = explode(" ",$name); 
  foreach($nword as $letter){ 
    $new_name .= $letter{0}.'.'; 
  } 
  return strtoupper($new_name); 
} 
echo initials('John Doe'); 
?>