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);
}
}