PHP 实现HASH表

class HashTable{		private $buckets;			//用于存储数据的数组	private $size = 12;			//记录buckets 数组的大小	public function __construct(){				$this->buckets = new SplFixedArray($this->size);		//SplFixedArray效率更高，也可以用一般的数组来代替	}		private function hashfunc($key){		$strlen = strlen($key); 	//返回字符串的长度		$hashval = 0;				for($i = 0; $i<$strlen ; $i++){			$hashval +=ord($key[$i]); //返回ASCII的值		}		return $hashval%$this->size;    //    返回取余数后的值	}	public function insert($key,$value){		$index = $this->hashfunc($key);	if(isset($this->buckets[$index])){        $newNode = new HashNode($key,$value,$this->buckets[$index]);			}else{	$newNode = new HashNode($key,$value,null);			}	$this->buckets[$index] = $newNode;		}		public function find($key){					$index = $this->hashfunc($key);						$current = $this->buckets[$index];			echo "</br>";			var_dump($current);			while(isset($current)){    //遍历当前链表				if($current->key==$key){    //比较当前结点关键字					return $current->value;				}				$current = $current->nextNode;				//return $current->value;			}			return NULL;		}	}

class HashNode{			public $key;		//关键字			public $value;		//数据			public $nextNode;	//HASHNODE来存储信息			public function __construct($key,$value,$nextNode = NULL){						$this->key = $key;						$this->value = $value;						$this->nextNode = $nextNode;									}		}

    $ht = new HashTable();     $ht->insert('key1','value1');     //$ht->insert('key12','value12');		echo $ht->find('key1');