java - Java字符串的默认值: null vs ""

Question

Java 字符串的默认值为“null”。但是，当我实例化该字符串时，它似乎是一个空字符串。有人可以解释一下吗？

class Stuff
{
    String a;
    String b = new String();
}

class Demo
{
    public static void main( String[] args )
    {
       Stuff s = new Stuff();
       System.out.println( s.a );
       System.out.println( s.b );

       if( s.b.equals( "" ) )
       {
            System.out.println( "true" );
       }
    }
}

Answer 1

String()构造函数 Javaodc 说，

Initializes a newly created String object so that it represents an empty character sequence. Note that use of this constructor is unnecessary since Strings are immutable.

这与您观察到的行为相符。