Thinking in Java 11.3 添加一组元素
程序员文章站
2022-05-07 10:49:49
...
功能:
过程:
-
类AddingGroups
1、初始化构造使用Arrays.asList方法添加
2、addAll方法
3、Collections.addAll方法(首推)
4、初始化使用Arrays.asList方法添加
5、更改元素
个人实现:
package thinking;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class AddingGroups {
public static void main(String[] args) {
//Collection<Integer> collection = new Collection<Integer>(Arrays.asList(1,2,3,4,5,6));
Collection<Integer> collection = new ArrayList<Integer>(Arrays.asList(1,2,3,4,5));
System.out.println(collection);
//collection.addAll(6,7,8,9,10);//失败
collection.addAll(collection);
System.out.println(collection);
Collections.addAll(collection, 6,7,8,9,10);
System.out.println(collection);
//Collections.addAll(collection, collection);//失败
List<Integer> list = Arrays.asList(11,12,13,14,15);//未写出,List勿引用错误
System.out.println(list);
list.set(0, 1);
System.out.println(list);
}
}
原书实现:
package thinkingjava;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class AddingGroups {
public static void main(String[] args) {
Collection<Integer> collection = new ArrayList<Integer>(Arrays.asList(1,2,3,4,5));
Integer[] moreInts = {6,7,8,9,10};
collection.addAll(Arrays.asList(moreInts));
Collections.addAll(collection, 11,12,13,14,15);
collection.addAll(Arrays.asList(moreInts));
List<Integer> list = Arrays.asList(16,17,18,19,20);
list.set(1, 99);
}
}
比较:
推荐阅读