[JAVA]數組轉換成字符串

所有類都繼承自Object類，Object裏有一個方法就是toString()，那麼所有的類創建的時候，都有一個toString的方法。
Object類中的toString()方法的源代碼如下：

    /**
     * Returns a string representation of the object. In general, the
     * {@code toString} method returns a string that
     * "textually represents" this object. The result should
     * be a concise but informative representation that is easy for a
     * person to read.
     * It is recommended that all subclasses override this method.
     * <p>
     * The {@code toString} method for class {@code Object}
     * returns a string consisting of the name of the class of which the
     * object is an instance, the at-sign character `{@code @}', and
     * the unsigned hexadecimal representation of the hash code of the
     * object. In other words, this method returns a string equal to the
     * value of:
     * <blockquote>
     * <pre>
     * getClass().getName() + '@' + Integer.toHexString(hashCode())
     * </pre></blockquote>
     *
     * @return  a string representation of the object.
     */
    public String toString() {
        return getClass().getName() + "@" + Integer.toHexString(hashCode());
    }

因爲數組類中並沒有對toString方法的重寫(override)，僅僅是重載(overload)爲類的靜態方法（參見java.util.Arrays）。所以，數組直接使用toString()的結果也是[類型@哈希值]。

所以數組轉爲字符串應寫成：Arrays.toString(A)

參考資料：http://www.cnblogs.com/ningvsban/p/3955483.html