这是因为,String java.lang.Object.toString()返回的确实是地址值,介绍如下:
Returns a string representation of the object. In general, the 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.
The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at character `@’, 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:
getClass().getName() + ‘@’ + Integer.toHexString(hashCode())
大体意思就是类Object的toString方法返回一个字符串,该字符串由对象为实例的类的名称、符号符号符号“@”和对象哈希代码的无符号十六进制表示组成。换句话说,此方法返回一个字符串。