求大神解答！

为什么要这样写？

studentList.add(new Student(1 + "", "yyz"));

studentList.add(new Student(2 + "", "cl"));

studentList.add(new Student(3 + "", "zyq"));

不这样写？有何区别?

studentList.add(new Student("1", "yyz"));

studentList.add(new Student("2", "cl"));

studentList.add(new Student("3", "zyq"));