本人做题的时候有个关于泛型的问题弄不清楚,望各位高手能予以解答,在此先谢谢各位了~Place code into the class so that it compiles and generates the output answer=42.
Note:Code options may be used more than once.public class _____{
private _____ object;
public _____ (_____ object){
this.o=object;
}
public _____ getobject(){
return object;
}
public static void main(String[] args) {
gen<String> str=new gen<String>("answer");
gen<Integer> intg=new gen<Integer>(42);
System.out.println(str.getobject()+"="+intg.getobject());
}
}
Code Option:Gen<T> ,Gen<?>,Gen,?,T
Note:Code options may be used more than once.public class _____{
private _____ object;
public _____ (_____ object){
this.o=object;
}
public _____ getobject(){
return object;
}
public static void main(String[] args) {
gen<String> str=new gen<String>("answer");
gen<Integer> intg=new gen<Integer>(42);
System.out.println(str.getobject()+"="+intg.getobject());
}
}
Code Option:Gen<T> ,Gen<?>,Gen,?,T
private T object;
public Gen (T object){
this.o=object; //这里应该是this.object
}
public T getobject(){
return object;
}
public static void main(String[] args) {
gen<String> str=new gen<String>("answer");
gen<Integer> intg=new gen<Integer>(42);
System.out.println(str.getobject()+"="+intg.getobject());
}
}
Code Option:Gen<T> ,Gen<?>,Gen,?,T
T
Gen<T>
T
T
private T object;
public Gen (T object){
this.object=object; //这里应该是this.object
}
public T getobject(){
return object;
}
public static void main(String[] args) {
Gen<String> str=new Gen<String>("answer");
Gen<Integer> intg=new Gen<Integer>(42);
System.out.println(str.getobject()+"="+intg.getobject());
}
}
谢谢Rick_ang(东方未名)的解答,可不可以大概解释一下?