[고급자바] 제너릭 (2)

package kr.or.ddit.basic;
 
import java.util.ArrayList;
import java.util.List;
 
class Util2{
    
    public static <T extends Number> int compare(T t1, T t2) {
        
        double v1 = t1.doubleValue();
        double v2 = t2.doubleValue();
        
        return Double.compare(v1, v2);
        
    }
}
public class T04GenericMethodTest {
    public static void main(String[] args) {
        
        int result1 = Util2.compare(10, 20);
        System.out.println(result1);
        
        int result2 = Util2.compare(3.14, 3);
        System.out.println(result2);
        
        //Util2.compare("C", "JAVA");
        
        List<?> list = new ArrayList<Number>(); // ?: 와일드카드
        
    }
    
 
}