为什么声明public Map<String,Student> students之后不直接=new HashMap<String,Student>() 而是在构造函数中
public Map<String,Student> students;
public MapTest(){
this.students = new HashMap<String,Student>();
}
public Map<String,Student> students;
public MapTest(){
this.students = new HashMap<String,Student>();
}
2016-04-06
举报