Java 参数的一些心得

java 对象入参是传入的是引用(一块内存), 基础类型是值(复制内容),测试代码如下

public class TestA {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

public class TestB {
    
    public void createTestA() {
        int id = 100;
        TestA testA = new TestA();
        testA.setName("chenjun");
        System.out.println("createTestA");
        System.out.println(id);
        System.out.println(testA.getName());
        altTestA(testA, id);
        System.out.println("after call altTestA");
        System.out.println(id);
        System.out.println(testA.getName());
    }

    public void altTestA(TestA testA, int id) {
        testA.setName("zhanglan");
        id = 200;
    }    

    public static void main(String[] args) {
        TestB test = new TestB();
        test.createTestA();
    }
}

运行结果

createTestA
100
chen
after call altTestA
100
zhang