Java 变量名不是引用本身

Java里面对象的传递是通过对象的引用,而引用又是用变量名表示的,但是注意变量名不是引用本身。如下示例程序:

变量c的重新赋值并不影响之前表示的引用(对象)。

 

/*
 * @(#)PassedReferenceWillNotChange.java	2014年5月7日
 *
 * Copyright (c) 2014 Wu Owen. All rights reserved.
 */

package com.labj.main;

/**
 * Passed object c is stored in B, when c is assigned to another object, object stored in B will not
 * change.
 * 
 * @author owen
 */
public class PassedReferenceWillNotChange {

	public static void main(String[] args) {
		C c = new C(1);
		B b = new B(c);
		System.out.println("A.f()");
		c = new C(2);
		// b.setC(c);
		b.g();
	}
}

class B {
	C c;

	public B(C c) {
		this.c = c;
	}

	void g() {
		System.out.println("B.g()");
		System.out.println("c.getId(): " + c.getId());
	}

	void setC(C c) {
		this.c = c;
	}
}

class C {
	int id;

	public C(int id) {
		this.id = id;
	}

	int getId() {
		return id;
	}
}

 

 

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