abstract class Strategy{
     public abstract void AlgorithmInterface();
}
class StrategyA extend Strategy{
     public AlgorithmInterface(){ //A實現 };
}
class StrategyB extend Strategy{
     public AlgorithmInterface(){ //B實現 };
}
class StrategyC extend Strategy{
     public AlgorithmInterface(){ //C實現 };
}
class Context(){
     Strategy strategy;
     public Context(bufferType:Srting){      //可以搭配簡單工廠模式一起使用
          var strategy = null;
　　　　　  switch(bufferType){
　　　　　　　　case "a":strategy = new StrategyA();
　　　　　　　　case "b":strategy = new StrategyB();
　　　　　　　　case "c":strategy = new StrategyC();
　　　　　　}
　　　　   this.strategy = buffer;
     }
     public ContextInterface(){
          this.strategy.AlgorithmInterface();
     }
}

class Main{
　　Context context = new Context("a");
　　context.ContextInterface();
}