问题1--static final关键词

Posted 2020-10-31 小熊hit

如下面所述代码，scf输出scf = SelfCounter id，后面id递增，可以理解。而由于scsf被static final修饰了，无论再new多少次输出都不会变，但是为什么输出是0而不是1呢？百思不得解，小白求拍求解答！

class SelfCounter {
　　private static int count;
　　private int id = count++;
　　public String toString() { return "SelfCounter " + id; }
}

class WithFinalFields {
　　final SelfCounter scf = new SelfCounter();
　　static final SelfCounter scsf = new SelfCounter();
　　public String toString() {
　　　　return "scf = " + scf + "\nscsf = " + scsf;
　　}
}
public class Final_Static {
　　public static void main(String args[]) {
　　　　System.out.println("First object:");
　　　　System.out.println(new WithFinalFields());
　　　　System.out.println("Second object:");
　　　　System.out.println(new WithFinalFields());
　　　　System.out.println("Third object:");
　　　　System.out.println(new WithFinalFields());
　　}
}/* Output: 

First object:
scf = SelfCounter 1
scsf = SelfCounter 0
Second object:
scf = SelfCounter 2
scsf = SelfCounter 0
*///:~