java中讲讲PrintStream的用法,举例?



1.2 PrintStream的用法  


马 克-to-win:从学java第一天,我们就经常用到System.out.println(),实际上查阅文档可知,System.out就是Sun 编的一个PrintStream的实例对象。PrintStream顾名思义,Sun编它,就是用来打印的,以各种各样的格式,打印各种各样的数据, (boolean,char,double,float)。下面的例子就介绍了println(int x),print(String)和print(char c)的用法。


例:1.2.1

import java.io.*;

public class TestMark_to_win {

    public static void main(String args[]) throws Exception {

        byte inp[] = new byte[3];

        inp[0] = 97;inp[1] = 98;inp[2] = 99;

        for (int i = 0; i < 3; i++) {

            /*there is no such method as println(Byte x), only sun. have the

following public void println(int x) if you want to print out

"a", use System.out.println((char)inp[i]);*/

            System.out.println(inp[i]);

        }


        for (int i = 0; i < 3; i++) {

/*public void print(char c)Print a character.*/

            System.out.println((char) inp[i]);

        }

        char c='z';

        System.out.println(c);

        String s="我们是good123";

        System.out.println(s);

        double d=3.14;

        System.out.println(d);

    }

}