Question

java一道题

若需要指定泛型参数是某个类或其子类实例，应该使用什么关键字

Answer 1

Public Rectangle(){this(5,6)}
public Rectangle(int width,int length){
this.width=width;
this.length=length;
}
public String toString(){
return "[width="+width+";length="+length+"]"
}