Java out println how is this possible

Question

I ve seen some code such as   out println  print something      I tried import java lang System   but it s not working  How do you use out println

User · Answer

simply import    import static java lang System

User · Answer

static imports do the trick   import static java lang System out    or alternatively import every static method and field using  import static java lang System        Addendum by  Steve C  note that  sfussenegger said this in a comment on my Answer       Using such a static import of System out isn t suited for more than simple run-once code     So please don t imagine that he  or I  think that this solution is Good Practice

User · Answer

PrintStream out   System out  out println   hello

User · Answer

you can see this also in sockets      PrintWriter out   new PrintWriter socket getOutputStream      out println  hello

User · Answer

You will have to create an object out first  More about this here          write to stdout     out   System out      out println  Test 1        out close

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Well  you would typically use  System out println  print something      which doesn t require any imports  However  since out is a static field inside of System  you  could write use a static import like this   import static java lang System     class Test       public static void main String   args            out println  print something              Take a look at this link  Typically you would only do this if you are using a lot of static methods from a particular class  like I use it all the time for junit asserts  and easymock

User · Answer

Or simply   System out println  Some text

User · Answer

sfussenegger s answer explains how to make this work   But I d say don t do it   Experienced Java programmers use  and expect to see           System out println         and not           out println         A static import of System out or System err is  IMO  bad style because    it breaks the accepted idiom  and it makes it harder to track down unwanted trace prints that were added during testing and not removed    If you find yourself doing lots of output to System out or System err  I think it is a better to abstract the streams into attributes  local variables or methods   This will make your application more reusable

User · Answer

out is a PrintStream type of static variable object  of System class and println   is function of the PrintStream class   class PrintStream       public void println          member function            class System       public static final PrintStream out      data member             That is why the static variable object  out is accessed with the class name System which further invokes the method println   of it s type PrintStream  which is a class

[java] Java out.println() how is this possible?

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