截取字符串"Mon Tues Wed Thur Fri Sat Sun."，空格为各个截取点，并依次输出
public class Demo9_2 {
public static void main(String[] args) {
String s1=new String("Mon Tues Wed Thur Fri Sat Sun.");
//单词的抽取是重复的：循环
int index1=s1.indexOf('.');
String s2=s1.substring(0,index1);
//表示空格的位置
int index2=0;
///循环次数未知
while(true)
{
index2=s2.indexOf(' ');
if(index2!=-1)
{
System.out.println(s2.substring(0,index2));
s2=s2.substring(index2+1);
}
else
{
System.out.println(s2);
break;
}
}
}
}
1.int index1=s1.indexOf('.');取字符串尾部'.'的索引，String s2=s1.substring(0,index1);截取Mon Tues Wed Thur Fri Sat Sun字符串去掉'.'
2.s2=s2.substring(index2+1);以空格后的字符开始循环截取
