在
PHP中给出以下内容：
<?PHP
class foo {
public $bar;
function __construct() {
"Foo Exists!";
}
function magic_bullet($id) {
switch($id) {
case 1:
echo "There is no spoon! ";
case 2:
echo "Or is there... ";
break;
}
}
}
class bar {
function __construct() {
echo "Bar exists";
}
function target($id) {
echo "I want a magic bullet for this ID!";
}
}
$test = new foo();
$test->bar = new bar();
$test->bar->target(42);
我想知道’bar’类是否可以调用’foo’类的’magic bullet’方法. ‘bar’实例包含在’foo’实例中,但与它没有父/子关系.实际上,我有很多不同的“条形”类,“foo”在一个数组中,每个类都有一些与$id不同的东西,然后想要将它传递给“magic_bullet”函数以获得最终结果,因此禁止结构更改类关系,是否可以访问“容器”实例的方法？
您必须修改代码才能提供关系.在OOP中,我们称之为
aggregation.
假设PHP 4,以及“一系列条形图”的想法
<?PHP
class foo {
var $bars = array();
function __construct() {
"Foo Exists!";
}
function magic_bullet($id) {
switch($id) {
case 1:
echo "There is no spoon! ";
case 2:
echo "Or is there... ";
break;
}
}
function addBar( &$bar )
{
$bar->setFoo( $this );
$this->bars[] = &$bar;
}
}
class bar {
var $foo;
function __construct() {
echo "Bar exists";
}
function target($id){
if ( isset( $this->foo ) )
{
echo $this->foo->magic_bullet( $id );
} else {
trigger_error( 'There is no foo!',E_USER_ERROR );
}
}
function setFoo( &$foo )
{
$this->foo = &$foo;
}
}
$test = new foo();
$bar1 = new bar();
$bar2 = new bar();
$test->addBar( $bar1 );
$test->addBar( $bar2 );
$bar1->target( 1 );
$bar1->target( 2 );