Hello Jiong, +1
+1s
public class Person {
private long age = 0;
public void plus1s(Person elder) {
elder.age += 1;
this.age -= 1;
}
}
+1s
public class Person {
private long age = 0;
public void plus1s(Person elder) {
elder.age += 1;
this.age -= 1;
}
}