PHP design pattern combination pattern

PHP design pattern combination pattern belongs to structural pattern

Overview: Combine objects into a tree structure to represent the 'partial-uniyun' hierarchy. The combination mode ensures consistency between the use of a single object and a composite object.

Both combination and aggregation describe the situation where a class holds one or more instances of other classes for a long time.

Aggregation: contained objects are the core part of the container, but they can also be contained by other objects. The aggregation relationship is illustrated by a line starting with a hollow diamond.

Combination: the contained object can only be referenced by its container. When the container is deleted, it should also be deleted. The Diamond of the composite relationship is solid.

/**

* Execution unit

*/

Abstract class Unit {

Public function bombardStrength ();

}

/**

* Archer

*/

Class ArcherUnit extends Unit {

Public function bombardStrength (){

Return 4;

}

}

/**

* Laser cannon

*/

Class LaserCannonUnit extends Unit {

Public function bombardStrength (){

Return 10;

}

}

/**

* Army

*/

Class Arm {

Private $ units = array ();

Private $ strength = 0;

Public function addUnit (Unit $ unit ){

Array_push ($ this-> units, $ unit );

}

Public function bombardStrength (){

Foreach ($ this-> units as $ unit ){

$ This-> strength + = $ unit-> bombardStrength ();

}

}

}

/**

* Combination mode

*/

Public function actionCombine (){

$ Archer = new ArcherUnit;

$ LaserCannon = new LaserCannonUnit;

$ Arm = new Arm;

$ Arm-> addUnit ($ archer );

$ Arm-> addUnit ($ laserCannon );

Echo $ arm-> bombardStrength ();

}