ListDemo(通过List接口的实现类ArrayList实现)

ListDemo(通过List接口的实现类ArrayList实现需求)

元素个数不确定

要求获得元素的实际个数

按照存储顺序获取并打印元素信息

package

com1018;

import

java.util.ArrayList;

import

java.util.Iterator;

import

java.util.List;

/**

*

*

 

@author a496006

* store many Penguin info, get Penguin info, print out each penguin's info

*/

public

class CollectionDemo {

publicstaticvoid main(String[] args) {

Penguin

p1 = new Penguin("dajiao", "male");

Penguin

p2 = new Penguin("qq", "female");

 

List<Penguin>

list = new ArrayList<>();

list.add(p1);

list.add(p2);

 

System.

out.println("total" + " " + list.size() + " " + "penguins");

for (Penguin obj : list) {

System.

out.println(obj.getName() + "\t" + obj.getGender());

}

 

Iterator<Penguin>

it = list.iterator();

System.

out.println("total" + " " + list.size() + " " + "penguins");

while (it.hasNext()) {

Penguin

p = it.next();

System.

out.println(p.getName() + "\t" + p.getGender());

 

}

}

}

package

com1018;

public

class Penguin {

private String name;

private String gender;

public Penguin(String name, String gender) {

this.name = name;

this.gender = gender;

 

//System.out.println("running this constructor");

}

public String getName() {

returnname;

}

publicvoid setName(String name) {

this.name = name;

}

public String getGender() {

returngender;

}

publicvoid setGender(String gender) {

this.gender = gender;

}

}