package c03;
//: c03:RandomBounds.java
// Does Math.random() produce 0.0 and 1.0?
// {RunByHand}
// From 'Thinking in Java, 3rd ed. ' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
public class RandomBounds {
static void usage() {
System.out.println( "Usage: \n\t " +
"RandomBounds lower\n\tRandomBounds upper ");
System.exit(1);
}
public static void main(String[] args) {
if(args.length != 1) usage();
if(args[0].equals( "lower ")) {
while(Math.random() != 0.0)
; // Keep trying
System.out.println( "Produced 0.0! ");
}
else if(args[0].equals( "upper ")) {
while(Math.random() != 1.0)
; // Keep trying
System.out.println( "Produced 1.0! ");
}
else
usage();
}
}
运行这个程序,为什么没有提示我输入什么东西呢?
------解决方案--------------------
你应当在运行的时候输入参数,比如运行:
java c03.RandomBounds lower
------解决方案--------------------
eclipse中输入参数是一件很简单的事情,步骤如下:
1.点菜单里的Run
2.点击菜单里的[Run...]
3.弹出一个画面:Create,Manage,and run configuration
4.双击Java Application
5.在Mian class 那里找到你的Mian class
6.点击(x)=Argument选项卡,在Parogram argumerts:处输入你的参数就可以了.
7.点击Run button就可以了.
最后你在main方法里就可以接收到你输入的参灵数.