关于 tostring

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#1 Created at ... [Delete] [Delete and Lock User]

public class Main {

public static void main(String[] args) {

Weekday day = Weekday.SUN;

if (day.dayValue == 6 || day.dayValue == 0) {

System.out.println("Today is " + day + ". Work at home!");

} else {

System.out.println("Today is " + day + ". Work at office!");

}

enum Weekday {

MON(1, "星期一"), TUE(2, "星期二"), WED(3, "星期三"), THU(4, "星期四"), FRI(5, "星期五"), SAT(6, "星期六"), SUN(0, "星期日");

public final int dayValue;

private final String chinese;

private Weekday(int dayValue, String chinese) {

this.dayValue = dayValue;

this.chinese = chinese;

}

@Override

public String toString() {

return this.chinese;

}

为什么 day 的打印输出值是星期天没看见在哪里调用了 tostring 方法啊。。。

#2 Created at ... [Delete] [Delete and Lock User]

看评价：

system.out.println本质上调用的是class 的 toString()方法，在class 重写了 toString()方法，所以导致返回的是chinese，也就是第二个参数。

#3 Created at ... [Delete] [Delete and Lock User]

day不就是相当于一个class的实例吗