一個關於<T>泛型的例子

public class GenericAdd{ 
     
    //泛型方法實現兩個數相加 
    public <T extends Number> double add(T t1, T t2){ 
        double sum = 0.0; 
        sum = t1.doubleValue() + t2.doubleValue(); return sum; 
    } 
    public static void main(String[] args){ 
        test(); 
    } 
     
    public static void test(){ 
        GenericAdd addTest = new GenericAdd();//新建GenericAdd類 
         
        int num1 = 3; 
        int num2 = 4; 
        System.out.println("整數和:"+addTest.add(num1, num2));//整數相加 
         
        float num3 = 3.0f; 
        float num4 = 7.0f; 
        System.out.println("浮點數和:"+addTest.add(num3, num4));//浮點數相加 
         
        double num5 = 99.0; 
        double num6 = 1.0; 
        System.out.println("雙精度浮點數和:"+addTest.add(num5, num6));//雙精度浮點數相加 
         
        long num7 = 300; 
        long num8 = 700; 
        System.out.println("長整數和:"+addTest.add(num7, num8));//長整數相加 
    } 
}