php內核之數組

一、zend_hash_num_elements 獲取數組元素個數。宏定義以下：

1 #define zend_hash_num_elements(ht) \
2     (ht)->nNumOfElements

二、ZEND_HASH_FOREACH_KEY_VAL 遍歷數組鍵值。使用方法：

1 ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(array), num_key, string_key, entry) { 2             // code
3 } ZEND_HASH_FOREACH_END();

　ZEND_HASH_FOREACH_KEY_VAL是個宏函數：

1 #define ZEND_HASH_FOREACH_KEY_VAL(ht, _h, _key, _val) \
2     ZEND_HASH_FOREACH(ht, 0); \ 3     _h = _p->h; \ 4     _key = _p->key; \ 5     _val = _z;

　繼續展開 ZEND_HASH_FOREACH：數組

1 #define ZEND_HASH_FOREACH(_ht, indirect) do { \
2         Bucket *_p = (_ht)->arData; \ 3         Bucket *_end = _p + (_ht)->nNumUsed; \ 4         for (; _p != _end; _p++) { \ 5             zval *_z = &_p->val; \ 6             if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) { \ 7                 _z = Z_INDIRECT_P(_z); \ 8  } \ 9             if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue;

ZEND_HASH_FOREACH_END展開：

1 #define ZEND_HASH_FOREACH_END() \
2  } \ 3     } while (0)

ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(array), num_key, string_key, entry) { // code } ZEND_HASH_FOREACH_END();
徹底展開：

 1 do {  2     Bucket *_p = (_ht)->arData;  // Z_ARRVAL_P(array) ---> ht ---> _ht
 3     Bucket *_end = _p + (_ht)->nNumUsed;  // 起始地址+偏移地址
 4     for (; _p != _end; _p++) {  5         zval *_z = &_p->val;  6         if (indirect && Z_TYPE_P(_z) == IS_INDIRECT) {  7             _z = Z_INDIRECT_P(_z);  8  }  9         if (UNEXPECTED(Z_TYPE_P(_z) == IS_UNDEF)) continue; 10         _h = _p->h;  // zend_ulong num_key ---> _h
11         _key = _p->key; // zend_string *string_key ---> _key
12         _val = _z; // zval *entry ---> _val
13  { 14            //code
15  } 16  } 17 } while (0)