List遍历的几种方式以及几种基本的增删改查
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ListTest {
public static void main(String[] args) {
List<Person> list = new ArrayList<>();
Person p1 = new Person("zhouyu", 22, "jiangsu");
Person p2 = new Person("liubei", 33, "sichuan");
Person p3 = new Person("caocao", 44, "henan");
list.add(p1);
list.add(p2);
list.add(p3);
Iterator<Person> iterator = list.iterator();
// 方式1 迭代器
while (iterator.hasNext()) {
Person person = iterator.next();
System.out.println(person);
}
System.out.println("-+_+_+_+_+_+_+_-");
// 方式2 普通for
for (int i = 0; i < list.size(); i++) {
Person person = (Person) list.get(i);
System.out.println(person);
}
System.out.println("-+_+_+_+_+_+_+_-");
// 方式3 增强for
for (Object object : list) {
Person person = (Person) object;
System.out.println(person);
}
System.out.println("-+_+_+_+_+_+_+_-");
Person person = new Person("zhangsan", 23, "zhangcun");
// 列表的修改功能
list.set(2, person);
// 自带的toString方法
System.out.println(list.toString());
System.out.println("-+_+_+_+_+_+_+_-");
// 列表的截取功能 从指定位置开始截取到指定位置结束
System.out.println(list.subList(1, 3));
// [Person [name=liubei, age=33, address=sichuan], Person
// [name=zhangsan, age=23, address=zhangcun]]
// 获取指定索引 的元素
System.out.println(list.get(0));
}
}
package cn.spring01.ArrayList;
public class Person {
private String name;
private int age;
private String address;
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + ", address=" + address + "]";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public Person(String name, int age, String address) {
super();
this.name = name;
this.age = age;
this.address = address;
}
}
Person [name=zhouyu, age=22, address=jiangsu]
Person [name=liubei, age=33, address=sichuan]
Person [name=caocao, age=44, address=henan]
-+_+_+_+_+_+_+_-
Person [name=zhouyu, age=22, address=jiangsu]
Person [name=liubei, age=33, address=sichuan]
Person [name=caocao, age=44, address=henan]
-+_+_+_+_+_+_+_-
Person [name=zhouyu, age=22, address=jiangsu]
Person [name=liubei, age=33, address=sichuan]
Person [name=caocao, age=44, address=henan]
-+_+_+_+_+_+_+_-
[Person [name=zhouyu, age=22, address=jiangsu], Person [name=liubei, age=33, address=sichuan], Person [name=zhangsan, age=23, address=zhangcun]]
-+_+_+_+_+_+_+_-
[Person [name=liubei, age=33, address=sichuan], Person [name=zhangsan, age=23, address=zhangcun]]
Person [name=zhouyu, age=22, address=jiangsu]