php 源码解析--count
PHP_FUNCTION(count){
zval *array;
long mode = COUNT_NORMAL;//解析参数,z|l的形式表示第二个参数可选，PHP内部默认为COUNT_NORMAL
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z|l", &array, &mode) == FAILURE) {return;
}switch (Z_TYPE_P(array)) {case IS_NULL://count(NULL)这种直接返回1
RETURN_LONG(0);break;case IS_ARRAY://count(array(...))会递归计算
RETURN_LONG (php_count_recursive (array, mode TSRMLS_CC));break;case IS_OBJECT: {#ifdef HAVE_SPL
zval *retval;#endif
/* first, we check if the handler is defined */
//这里没看明白~~后面补上
if (Z_OBJ_HT_P(array)->count_elements) {
RETVAL_LONG(1);if (SUCCESS == Z_OBJ_HT(*array)->count_elements(array, &Z_LVAL_P(return_value) TSRMLS_CC)) {return;
}
}#ifdef HAVE_SPL
//count(Obj)
//如果obj实现了SPL中的Countable接口，即实现了count函数，则会调用这个函数，并用这个函数的输出作为最终的count的返回值
/**
* class Test implements Countable{
* public function count(){
* return 5;
* }
* }
* $test=new Test();
* 那么count($test)=5
*/
/* if not and the object implements Countable we call its count() method */
if (Z_OBJ_HT_P(array)->get_class_entry && instanceof_function(Z_OBJCE_P(array), spl_ce_Countable TSRMLS_CC)) {
zend_call_method_with_0_params(&array, NULL, NULL, "count", &retval);if (retval) {
convert_to_long_ex(&retval);
RETVAL_LONG(Z_LVAL_P(retval));
zval_ptr_dtor(&retval);
}return;
}#endif
}default://其他的一概返回1，比方说
//count("hello world")=1
//count(123)=1等等
RETURN_LONG(1);break;
}
}
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