样例 1:
下列程序的输出结果？

public class Test {
    public static void test(StringBuffer str1, String str2) {
        str1.append(“, World!”);
        str2 = “World”;
    }
    public static void main(String[] args) {
        StringBuffer string1 = new StringBuffer(“Hello”);
        String string2 = “Hello”;
        test(string1, string2);
        System.out.println(“string1: “ + string1);
        System.our.println(“string2: “ + string2);
    }
}
//output:
//string1: Hello, World!
//string2: Hello

class Value {
    public int i = 15;
}
public class Test {
    public static void main(String[] args) {
        Test t = new Test();
        t.first();
    }
    public void first() {
        int i = 5;
        Value v = new Value;
        v.i = 25;
        second(v, i);
        System.out.println(v.i);
    }
    public void second(Value v, int i) {
        i = 0;
        v.i = 20;
        Value val = new Value();
        v = val;
        System.out.println(v.i + “ “ + i);
    }
}
//output:
//15 0
//20

Java不管是值传递还是引用传递，传递的都是副本

赏

谢谢你请我喝咖啡

支付宝

微信