2
if($post_id === null) {
$this->db->insert($data);
!isset($data[$this->page_id]) || $data[$this->page_id] = NULL;
}
if($post_id === null) {
$this->db->insert($data);
!isset($data[$this->page_id]) || $data[$this->page_id] = NULL;
}
逻辑运算符执行short-circuit evaluation。 如果逻辑OR的第一部分为真,则整个表达式为真,因此不需要评估第二部分。
它是做什么等同于:
if(isset($data[$this->page_id])){
$data[$this->page_id] = NULL
}
为了举例说明如何工作的实例,从documentation:
// foo() will never get called as those operators are short-circuit
$a = (false && foo());
$b = (true || foo());