本文实例讲述了PHP面向对象程序设计组合模式与装饰模式。，具体如下：
组合模式
定义：组合模式定义了一个单根继承体系，使具有截然不同职责的集合可以并肩工作。
一个军队的案例，
<?php
abstract class Unit { // 个体
abstract function bombardStrength();
}
class Archer extends Unit { // 弓箭手
function bombardStrength() {
return 4;
}
}
class LaserCannonUnit extends Unit { // 火炮手
function bombardStrength() {
return 44;
}
}
?>
军队整合成员，输出火力
<?php
abstract class Unit {
abstract function bombardStrength();
}
class Archer extends Unit {
function bombardStrength() {
return 4;
}
}
class LaserCannonUnit extends Unit {
function bombardStrength() {
return 44;
}
}
class Army { // 军队
private $units = array(); // 定义私有属性 个体集
function addUnit( Unit $unit ) { // 添加成员
array_push( $this->units, $unit );
}
function bombardStrength() { // 火力
$ret = 0;
foreach( $this->units as $unit ) {
$ret += $unit->bombardStrength();
}
return $ret;
}
}
$unit1 = new Archer();
$unit2 = new LaserCannonUnit();
$army = new Army();
$army->addUnit( $unit1 );
$army->addUnit( $unit2 );
print $army->bombardStrength(); // 输出火力
?>
output:
48
军队进一步整合其他军队
<?php
abstract class Unit {
abstract function bombardStrength();
}
class Archer extends Unit {
function bombardStrength() {
return 4;
}
}
class LaserCannonUnit extends Unit {
function bombardStrength() {
return 44;
}
}
class Army {
private $units = array();
private $armies= array();
function addUnit( Unit $unit ) {
array_push( $this->units, $unit );
}
function addArmy( Army $army ) {
array_push( $this->armies, $army );
}
function bombardStrength() {
$ret = 0;
foreach( $this->units as $unit ) {
$ret += $unit->bombardStrength();
}
foreach( $this->armies as $army ) {
$ret += $army->bombardStrength();
}
return $ret;
}
}
$unit1 = new Archer();
$unit2 = new LaserCannonUnit();
$army = new Army();
$army->addUnit( $unit1 );
$army->addUnit( $unit2 );
print $army->bombardStrength();
print "n";
$army2 = clone $army; // 克隆军队
$army->addArmy( $army2 );
print $army->bombardStrength();
print "n";
?>
output:
48
96
更好的方式，支持新增，移除等等其他功能。
<?php
abstract class Unit {
abstract function addUnit( Unit $unit );
abstract function removeUnit( Unit $unit );
abstract function bombardStrength();
}
class Army extends Unit { // 军队
private $units = array();
function addUnit( Unit $unit ) {
if ( in_array( $unit, $this->units, true ) ) { // $this用于调用正常的属性或方法，self调用静态的方法，属性或者常量
return;
}
$this->units[] = $unit;
}
function removeUnit( Unit $unit ) {
// >= php 5.3
$this->units = array_udiff( $this->units, array( $unit ),
function( $a, $b ) { return ($a === $b)?0:1; } );
// < php 5.3
// $this->units = array_udiff( $this->units, array( $unit ),
// create_function( '$a,$b', 'return ($a === $b)?0:1;' ) );
// 对象数组，create_function,创建函数
}
function bombardStrength() {
$ret = 0;
foreach( $this->units as $unit ) {
$ret += $unit->bombardStrength();
}
return $ret;
}
}
// quick example classes
class Tank extends Unit { // 坦克
function addUnit( Unit $unit ) {}
function removeUnit( Unit $unit ) {}
function bombardStrength() {
return 4;
}
}
class Soldier extends Unit { // 士兵
function addUnit( Unit $unit ) {}
function removeUnit( Unit $unit ) {}
function bombardStrength() {
return 8;
}
}
$tank = new Tank();
$tank2 = new Tank();
$soldier = new Soldier();
$army = new Army();
$army->addUnit( $soldier );
$army->addUnit( $tank );
$army->addUnit( $tank2 );
print_r( $army );
print $army->bombardStrength()."n";
$army->removeUnit( $soldier );
print_r( $army );
print $army->bombardStrength()."n";
?>
