CachingIterator::offsetExists
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
CachingIterator::offsetExists — The offsetExists purpose
說明
   public CachingIterator::offsetExists(string 
  
  $key): bool警告
  
 本函式還未編寫文件,僅有參數列表。
參數
- 
key
- 
      The index being checked. 
返回值
   Returns true if an entry referenced by the offset exists, false otherwise.