我在练习JAVA.util包时出现的问题,import java.util.ArrayList;
import java.util.Collections;class mailAddressTest{
ArrayList alist;
mailAddressTest(){
alist = new ArrayList();
}
void add(){
for(int cap = 0;cap < 15;cap++){
alist.add(new Integer(cap));
}
alist.add("David Clarks");
alist.add("10 Downing Street");
alist.add("LondonState:London");
alist.add("United Kingdom");
alist.add("110022");
alist.add("John Lenon");
alist.add("12 Park Avenue");
alist.add("GalistiforniaState:Galistifornia");
alist.add("USA");
alist.add("210033");
alist.add("Stefii Graff");
alist.add("14 Maple Lane");
alist.add("MahomaState :Sydeny");
alist.add("Australistia");
alist.add("412033");
}
void display(){
System.out.println("********************************");
System.out.println("客户电子邮件地址");
System.out.println("********************************");
for(int cap = 0;cap <= alist.size();){
System.out.print("Name:"+alist.get(cap++));
System.out.println("Street:"+alist.get(cap++));
System.out.println("City:"+alist.get(cap++));
System.out.println("Country:"+alist.get(cap++));
System.out.println("PinCode"+alist.get(cap++));
if(cap%5==0)
System.out.println(" ");
}
}}
import java.util.Collections;class mailAddressTest{
ArrayList alist;
mailAddressTest(){
alist = new ArrayList();
}
void add(){
for(int cap = 0;cap < 15;cap++){
alist.add(new Integer(cap));
}
alist.add("David Clarks");
alist.add("10 Downing Street");
alist.add("LondonState:London");
alist.add("United Kingdom");
alist.add("110022");
alist.add("John Lenon");
alist.add("12 Park Avenue");
alist.add("GalistiforniaState:Galistifornia");
alist.add("USA");
alist.add("210033");
alist.add("Stefii Graff");
alist.add("14 Maple Lane");
alist.add("MahomaState :Sydeny");
alist.add("Australistia");
alist.add("412033");
}
void display(){
System.out.println("********************************");
System.out.println("客户电子邮件地址");
System.out.println("********************************");
for(int cap = 0;cap <= alist.size();){
System.out.print("Name:"+alist.get(cap++));
System.out.println("Street:"+alist.get(cap++));
System.out.println("City:"+alist.get(cap++));
System.out.println("Country:"+alist.get(cap++));
System.out.println("PinCode"+alist.get(cap++));
if(cap%5==0)
System.out.println(" ");
}
}}
for(int cap = 0;cap <= alist.size();){
应该是cap<alist.size();而不能=alist.size();
//....
}catch(Exception e){
//....
}finally{
//....
}
alist.add(new Integer(cap));
}
加这些整数进去干嘛的呀?
前面会多出来这些的吧:
Name:0Street:1
City:2
Country:3
PinCode:4Name:5Street:6
City:7
Country:8
PinCode:9Name:10Street:11
City:12
Country:13
PinCode:14....
这是你希望的吗?if(cap%5==0)
System.out.println(" ");
这句没有必要判断吧?从0开始,++5次,肯定整除啊