我的代码是
public class Demo2 {
public static void main(String[] args) {
StringBuilder s=new StringBuilder("jaewkjldfxmopzdm");
for(int i=s.length()-3;i>=0;i=i-3){
s.insert(i,".");// TODO Auto-generated method stub
}
System.out.println("插入后的字符串为"+s);
}
}
public class Demo2 {
public static void main(String[] args) {
StringBuilder s=new StringBuilder("jaewkjldfxmopzdm");
for(int i=s.length()-3;i>=0;i=i-3){
s.insert(i,".");// TODO Auto-generated method stub
}
System.out.println("插入后的字符串为"+s);
}
}
2016-12-05
// 从后往前每隔三位插入逗号
for(int i = str.length();i > 0;i -= 3){
if(i == 16)
continue;
else
str.insert(i,',');
}
for(int i = str.length();i > 0;i -= 3){
if(i == 16)
continue;
else
str.insert(i,',');
}
2016-12-03
这里的主要难处就是怎么生成随机字符,我是这样做的:
String c = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
Random random = new Random();
c.charAt(random.nextInt(c.length()));
String c = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
Random random = new Random();
c.charAt(random.nextInt(c.length()));
2016-12-02