下面代码的输出结果是()。 list1 = [1,2,3] list2 = [4,5,6] print(list1+list2)
A.[5,7,9]
B.[1,2,3]
C.[4,5,6]
D.[1, 2, 3, 4, 5, 6]
- · 有5位网友选择 A,占比45.45%
- · 有3位网友选择 D,占比27.27%
- · 有2位网友选择 C,占比18.18%
- · 有1位网友选择 B,占比9.09%
A.[5,7,9]
B.[1,2,3]
C.[4,5,6]
D.[1, 2, 3, 4, 5, 6]
A、1 5
B、2 a
C、1 97
D、2 97
A、15
B、2a
C、197
D、297
A、1213
B、123
C、213
D、321
import Java.util.ArrayList;
import java.util.List;
(1) class AbstractFile{
protected String name;
public void printName(){System.out.println(name);}
public abstract boolean addChild(AbstractFile file);
public abstract boolean removeChild(AbstractF ile file);
public abstract List getChildren();
}
class File extends AbstractFile{
public File(String name){this.name=name;}
public boolean addChild(AbstractFile file){return false;}
public boolean removeChild(AbstractFile file){return false;}
public List getChildren(){return (2) ;}
}
class Folder extends AbstractFile{
private List childList;
public Folder(String name){
this.name=name;
this.childList=new ArrayList();
}
public boolean addChild(AbstractFile file) { return childList.add(file);}
public boolean removeChild(AbstractFile file){return childList.remove(file);}
public (3) getChildren(){return (4) ;}
}
public class Client{
public static void main(String[] args){
//构造一个树形的文件/目录结构
AbstractFile rootFolder= new Folder("c:\\ ");
AbstractFile compositeFolder=new Folder("composite");
AbstractFile windowsFolder=new Folder("windows");
AbstractFile file=new File("TestComposite.java");
rootFolder.addChild(compositeFolder) ;
rootFolder.addChild(windowsFolder);
compositeFolder.addChild(file) ;
//打印目录文件树
printTree(rootFolder);
}
private static void printTree(AbslractFile ifile){
ifile.printName();
List children=ifile.getChildreno:
if(children==null) return;
for (AbstractFile file:children) {
(5) ;
}
}
}
该程序运行后输出结果为:
c:\
composite
TestComposite.java
Windows
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