implicittostring.java

来自「是一款用JAVA 编写的编译器 具有很强的编译功能」· Java 代码 · 共 47 行

/*
 * Copyright 1999 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

/**
 * @test
 * @bug 4244408
 * @summary toString() should be called implicitly when += is used.
 *
 * @run main ImplicitToString
 */


// The failure for this test is a ClassCastException when the code is run.

import java.util.ArrayList;

public class ImplicitToString {
    public static void main(String[] args) {
	String s = "";
	ArrayList al = new ArrayList();
	al.add(new Object());

	// In the following line, toString() should be implicitly called.
	s += al.get(0);
    }
}