System.out.println vs PrintWriter

Question

Is there a difference in using these two? When would you use one over the other?

System.out.println(result);

versus

PrintWriter out = new PrintWriter(System.out);
out.println(result);
out.flush();

One's a PringStream and the other's a PrintWriter. PrintStreams can allow more flexibility with encoding. I'm guessing that some system encodings are used, but I'm not sure. — Hovercraft Full Of Eels, Dec 21 '13 at 18:23
`System.out` is a [PrintStream](http://docs.oracle.com/javase/7/docs/api/java/io/PrintStream.html) and `PrintWriter` is ... a [PrintWriter](http://docs.oracle.com/javase/7/docs/api/java/io/PrintWriter.html) — Brian Roach, Dec 21 '13 at 18:30
`PrintWriter` is also about twice as fast for printing text. — Luigi Plinge, Dec 06 '18 at 22:28

MultiplyByZer0 · Accepted Answer · 2019-03-22T03:34:08.043

12

The main difference is that System.out is a PrintStream and the other one is a PrintWriter. Essentially, PrintStream should be used to write a stream of bytes, while PrintWriter should be used to write a stream of characters (and thus it deals with character encodings and such).

For most use cases, there is no difference.

edited Mar 22 '19 at 03:34

answered Dec 21 '13 at 18:36

MultiplyByZer0

6,302
3
32
48

score 5 · Answer 2 · edited Dec 06 '18 at 22:26

5

System.out is instance of PrintStream

So your question narrows down to PrintStream vs PrintWriter

All characters printed by a PrintStream are converted into bytes using the platform's default character encoding. (Syso writes out directly to system output/console)
The PrintWriter class should be used in situations that require writing characters rather than bytes.

edited Dec 06 '18 at 22:26

Luigi Plinge

50,650
20
113
180

answered Dec 21 '13 at 18:35

Mitesh Pathak

1,306
10
14

score 4 · Answer 3 · answered Jul 26 '20 at 08:21

I recommend using PrintWriter if you have to print more than 10^3 lines in one go.

I got this by running these snippets 3 times each for n=10^1 to 10^7 and then taking mean of there execution time.

class Sprint{
    public static void main(String[] args) {
        int n=10000000;
        for(int i=0;i<n;i++){
            System.out.println(i);
        }
    }
}

import java.io.*;
class Pprint{
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        int n=10000000;
        for(int i=0;i<n;i++){
            out.println(i);
        }
        out.flush();
    }
}

score 0 · Answer 4 · edited Dec 21 '13 at 18:43

0

Yes, there is a slight difference. out.println() is short and is used in JSP while PrintWriter is used in servlets. out.println() is also derived from PrintWriter.

edited Dec 21 '13 at 18:43

MultiplyByZer0

6,302
3
32
48

answered Dec 21 '13 at 18:38

Muhammad

6,725
5
47
54

System.out.println vs PrintWriter

4 Answers4

Linked