java - 为什么我的程序只输出一个结果而不是五个？

Question

/*
 *Find if a year is leap or not
 */

public class LeapYear{

    private static int leapYear;

    public void setLeapYear(int leapYear){

        this.leapYear = leapYear;

    }// end method


    public static void main (String[] args) {
        LeapYear leap = new LeapYear();
        leap.setLeapYear(2010);
        leap.setLeapYear(2008);
        leap.setLeapYear(1900);
        leap.setLeapYear(2000);
        leap.setLeapYear(1565);

        // Is it Divisible by 4?
        if (leapYear % 4 == 0) {

            // Is it Divisible by 4 but not 100?
            if (leapYear % 100 != 0) {
                System.out.println(leapYear + ": is a leap year.");
            }
            // Is it Divisible by 4 and 100 and 400?
            else if (leapYear % 400 == 0) {
                System.out.println(leapYear + ": is a leap year.");
            }
            // It is Divisible by 4 and 100 but not 400!
            else {
                System.out.println(leapYear + ": is not a leap year.");
            }
        }
        // It is not divisible by 4.
        else {
            System.out.println(leapYear + ": is not a leap year.");
        }
    }
}

我是 Java 的新手，我编写了这段代码，以便它可以调用所有五年的 boolean 值并为所有这些值生成答案。但是它只调用最后一个。我该怎么做才对？

Answer 1

问题1

对 setLeapYear 的前四次调用:

leap.setLeapYear(2010);    // leap.leapYear = 2010;
leap.setLeapYear(2008);    // leap.leapYear = 2008;
leap.setLeapYear(1900);    // leap.leapYear = 1900;
leap.setLeapYear(2000);    // leap.leapYear = 2000;

被最后一个覆盖:

leap.setLeapYear(1565);    // leap.leapYear = 1565;

我可能会编写一个名为 isLeapYear(int year) 的 boolean 方法并执行

System.out.println(isLeapYear(2010));
System.out.println(isLeapYear(2008)); 
...

问题2

leapYear 是static，所以你不需要/不应该做 LeapYear leap = new LeapYear();(或者，你应该删除 static 修饰符)。