java基础面试题

Posted 2020-08-16 koushr

1.

public class A {
    public int i = 10;

    public static void test(A a) {
        a.i += 10;
    }

    public static void main(String[] args) {
        A a = new A();
        test(a);
        System.out.println(a.i);

        A b = a;
        test(b);
        System.out.println(a.i);
        System.out.println(b.i);

        A c = a;
        c.i = 0;

        System.out.println(c.i);
        System.out.println(b.i);
        System.out.println(a.i);
    }
}

考点有两个：第一，创建对象时内存的开辟。第二，参数的传递。本例中其实就只有一个对象，就是第一行的new A()，这将在堆内存中开辟一块空间，