are not called implicitly
php.net
<?php
class BaseClass{
function __construct()
{
print "In BaseClass constructor<br>";
}
} class SubClass extends BaseClass{
function __construct()
{
// parent::__construct();
print "In SubClass constructor<br>";
}
} class OtherSUbClass extends BaseClass{ }
$obj = new BaseClass();
$obj = new SubClass();
$obj = new OtherSubClass();
In BaseClass constructor
In SubClass constructor
In BaseClass constructor
<?php
class BaseClass{
function __construct()
{
print "In BaseClass constructor<br>";
}
} class SubClass extends BaseClass{
function __construct()
{
parent::__construct();
print "In SubClass constructor<br>";
}
} class OtherSUbClass extends BaseClass{ }
$obj = new BaseClass();
$obj = new SubClass();
$obj = new OtherSubClass();
In BaseClass constructor
In BaseClass constructor
In SubClass constructor
In BaseClass constructor
PHP 5 allows developers to declare constructor methods for classes. Classes which have a constructor method call this method on each newly-created object, so it is suitable for any initialization that the object may need before it is used.
Note: Parent constructors are not called implicitly if the child class defines a constructor. In order to run a parent constructor, a call to parent::__construct() within the child constructor is required. If the child does not define a constructor then it may be inherited from the parent class just like a normal class method (if it was not declared as private).
<?php
class MyDestructableClass{
function __construct()
{
print "In constructor\n";
$this->name = "MyDestructableClass";
} function __destruct()
{
// TODO: Implement __destruct() method.
print "Destroying ".$this->name."\n";
}
}
$obj = new MyDestructableClass();
In constructor Destroying MyDestructableClass
PHP 5 introduces a destructor concept similar to that of other object-oriented languages, such as C++. The destructor method will be called as soon as there are no other references to a particular object, or in any order during the shutdown sequence.
PHP 5 引入了析构函数的概念,这类似于其它面向对象的语言,如 C++。析构函数会在到某个对象的所有引用都被删除或者当对象被显式销毁时执行。
Like constructors, parent destructors will not be called implicitly by the engine. In order to run a parent destructor, one would have to explicitly call parent::__destruct() in the destructor body. Also like constructors, a child class may inherit the parent's destructor if it does not implement one itself.
The destructor will be called even if script execution is stopped using exit(). Calling exit() in a destructor will prevent the remaining shutdown routines from executing. 和构造函数一样,父类的析构函数不会被引擎暗中调用。要执行父类的析构函数,必须在子类的析构函数体中显式调用 parent::__destruct()。此外也和构造函数一样,子类如果自己没有定义析构函数则会继承父类的。
析构函数即使在使用 exit() 终止脚本运行时也会被调用。在析构函数中调用 exit() 将会中止其余关闭操作的运行。
are not called implicitly的更多相关文章
- IAR for msp430 MDK中 warning: #223-D: function "xxx" declared implicitly 解决方法
今天在EINT的范例里添加了一个函数,即eint.c中添加了一个datawrite()的函数,并在主函数main.c中调用,编译便警告 warning: #223-D: function " ...
- error X3025:global variables are implicitly constant, enable compatibility mode to allow modification
global variables are implicitly constant, enable compatibility mode to allow modification http://xbo ...
- Implicitly Typed Local Variables
Implicitly Typed Local Variables It happens time and time again: I’ll be at a game jam, mentoring st ...
- function "round" declared implicitly
keil工程代码,浮点计算中引用了数学库 math.h 中的round函数,但编译时出现告警 “warning: #223-D: function "round" declare ...
- unity c# script error CS0664: Literal of type double cannot be implicitly converted to type `float'. Add suffix `f' to create a literal of this type
例如在unity c# script中定义 private float x=0.0; 则会报 error CS0664: Literal of type double cannot be implic ...
- implicitly declaring function 'malloc' with type void *(unsigned long ) 错误 解决
errror : implicitly declaring function 'malloc' with type void *(unsigned long ) Be sure to includ ...
- 使用implicitly demo
泛型: Context Bounds // //定义一个隐式值, 这个值不能少, 要不找不到比较的对象 implicit val personCompartor = new Ordering[Per ...
- React报错之Parameter 'props' implicitly has an 'any' type
正文从这开始~ 总览 当我们没有为函数组件或者类组件的props声明类型,或忘记为React安装类型声明文件时,会产生"Parameter 'props' implicitly has an ...
- React报错之Parameter 'event' implicitly has an 'any' type
正文从这开始~ 总览 当我们不在事件处理函数中为事件声明类型时,会产生"Parameter 'event' implicitly has an 'any' type"错误.为了解决 ...
随机推荐
- 今天被坑了,而且被坑的好爽! 该死的UTF-8 有 BOM 格式编码
调一个项目,最后无法登录了. 排查到最后发现是cookie无法保存会话ID, 工作两年的经验这时候没用上. 开始一以为是PHP.ini的配置错了. 考虑过域名,浏览器问题. 脚本BUG. 最后最后一步 ...
- mysql操作类
同事今天推荐了一个mysql链接操作的类,地址 https://github.com/joshcam/PHP-MySQLi-Database-Class 大概看了一下,还是不错的,有点意思,先记录一 ...
- 【内网渗透笔记】Windows2008 R2搭建域控制器
0x00 前言 将网络中的多台计算机逻辑上组织到一起,进行集中管理,这种区别于工作组的逻辑环境叫做域(domain).域是日常计算机管理的一种很有效手段,因此,域控制器自然而然就在成域环境中最重要的角 ...
- Nginx 访问日志
配置访问日志: [root@localhost ~]$ cat /usr/local/nginx/conf/nginx.conf http { log_format main '$remote_add ...
- JS使用中碰到的一些问题
settimeout: 1.setTimeout(function () {//这个则会在1秒后进行弹出1 alert(1); }, 1000); 2.setTimeout(alert(1), 100 ...
- 【面试题】100IT名企java面试必考面试题
一.Java 基础部分 1. JAVA 的基本数据类型有哪些 ? String 是不是基本数据类型 ? Java 有 8 种基本数据类型: byte int ...
- 【本周主题】第一期:JavaScript单线程与异步
相信下边这个图一定都不陌生,本周就围绕这张图深入了解下js代码执行时的来龙去脉. 一.JavaScript是单线程的 2018-11-19 21:21:21 周一 js本质是单线程的.这一特性是jav ...
- ndk编译android的lame库
1.lame c库: https://github.com/intervigilium/liblame 下载后解压,进入目录,terminal里运行ndk-build即可 2.lame android ...
- 异构GoldenGate 12c 单向复制配置
1.分别在windows2008.linux平台部署oracle 11.2.0.4 2.分别在windows2008.linux平台部署gg. 2.1 windows平台: gg的安装目录位 C:\o ...
- filter对数组和对象的过滤
1,对数组的过滤 let arr = ['1', '2', '3'] let b = arr.filter(val => val === '2') console.log(b) // ['2] ...