java软件工程师学php - 7. Map被称作关联数组

java程序员学php - 7. Map被称作关联数组
如：
  $map['BJ'] = 'Beijing';
  $map['SH'] = 'Shanghai';

遍历这个关联数组：
  foreach($map as $abbr=>$full_name){
      echo "$abbr is short for $full_name";
  }