Java传递参数对实体的影响

1、当传递的为变量时，例如int、String类型，改变不会影响实体的变化

package com.oop;

public class Test {
    public static void main(String[] args) {
        int t = 1;
        A a = new A(t);
        System.out.println(t);
    }
}
class A {
    int t;
    public A (int t) {
        this.t = t;
        t = t + 1;
    }
}

输出t的值为1

2、当传递参数为类时，改变将会影响实体的变化

package com.oop;

public class Test {
    public static void main(String[] args) {
        A a = new A();
        a.t = 1;
        B b = new B(a);
        b.change();
        System.out.println(a.t);
    }
}
class A {
    int t;
}
class B {
    A a;
    public B(A a) {
        this.a = a;
    }
    public void change () {
        this.a.t = 100;
    }
}

输出a.t的值为100