写出【代码1】~【代码4】的输出结果。<br>import java.io.*;<br>public class E {<br>public

1.请说出E类中标注的【代码1】~【代码4】的输出结果____。(多个结果之间用#号隔开)。
import java.io.*;
public class E {
public static void main(String args]) {
int n=-1;
File f =new File("hello.txt");
byte ] a="abcd".getBytes();
try{ FileOutputStream out=new FileOutputStream(f);
out.write(a);
out.close();
FileInputStream in=new FileInputStream(f);
byte ] tom= new byte3];
int m = in.read(tom,0,3);
System.out.println(m); //【代码1】
String s=new String(tom,0,3);
System.out.println(s); //【代码2】
m = in.read(tom,0,3);
System.out.println(m); //【代码3】
s=new String(tom,0,3);
System.out.println(s); //【代码4】
}
catch(IOException e) {}
}
}

byte] a = "abcd".getBytes();
try {
FileOutputStream out = new FileOutputStream(f);
out.write(a);
out.close();
FileInputStream in = new FileInputStream(f);
byte] tom = new byte3];
int m = in.read(tom, 0, 3);
System.out.println(m); //【代码1】
String s=new String(tom,0,3); System.out.println(s); //【代码2】
m = in.read(tom, 0, 3);
System.out.println(m); //【代码3】
s = new String(tom, 0, 3);
System.out.println(s); //【代码4】
} catch (IOException e) {
}
}
}

">2.上机调试题：请说出E类中标注的【代码1】～【代码4】的输出结果。

import java.io.*;
public class E {
public static void main(String args]) {
int n = -1;
File f = new File("hello.txt");
byte] a = "abcd".getBytes();
try {
FileOutputStream out = new FileOutputStream(f);
out.write(a);
out.close();
FileInputStream in = new FileInputStream(f);
byte] tom = new byte3];
int m = in.read(tom, 0, 3);
System.out.println(m); //【代码1】
String s=new String(tom,0,3); System.out.println(s); //【代码2】
m = in.read(tom, 0, 3);
System.out.println(m); //【代码3】
s = new String(tom, 0, 3);
System.out.println(s); //【代码4】
} catch (IOException e) {
}
}
}

输出结果： 3 abc 1 abc

">3.1..请说出E类中标注的【代码1】~【代码4】的输出结果。 import java.io. *; public class E{ public static void main(String args ]){ int n= - 1; File f = new File( " hello.txt"); byte]a= "abcd" . getBytes(); try{ FileOutputStream out = new FileOutputStream(f); out.write(a); out.close(); FileInputStream in = new FileInputStream(f); byte] tom= new byte 3]; int m= in. read(tom, 0,3); System. out. println(m);//【代码1】 String s = new String(tom, 0, 3); System. out. println(s); //代码2】 m= in.read(tom, 0, 3); System. out. println(m);//代码3】 s = new String( tom, 0,3); System. out. println(s);//【代码4】 catch( IOException e){} } }

输出结果： 3 abc 1 abc

4.请说出E类中标注的【代码1】~【代码4】的输出结果____。(多个结果之间用#号隔开)。

import java.io.*;

public class E {

public static void main(String args]) {

int n=-1;

File f =new File("hello.txt");

byte ] a="abcd".getBytes();

try{ FileOutputStream out=new FileOutputStream(f);

out.write(a);

out.close();

FileInputStream in=new FileInputStream(f);

byte ] tom= new byte3];

int m = in.read(tom,0,3);

System.out.println(m); //【代码1】

String s=new String(tom,0,3);

System.out.println(s); //【代码2】

m = in.read(tom,0,3);

System.out.println(m); //【代码3】

s=new String(tom,0,3);

System.out.println(s); //【代码4】

}

catch(IOException e) {}

}

}（2.0分）

byte ] a="abcd".getBytes();

try{ FileOutputStream out=new FileOutputStream(f);

out.write(a);

out.close();

FileInputStream in=new FileInputStream(f);

byte ] tom= new byte3];

int m = in.read(tom,0,3);

System.out.println(m);

String s=new String(tom,0,3);

System.out.println(s);

m = in.read(tom,0,3);

System.out.println(m);

s=new String(tom,0,3);

System.out.println(s);

}

catch(IOException e) {}

}

">5.以下程序的运行结果是（）。

import java.io.*;

public class E {

public static void main(String args]) {

int n=-1;

File f =new File("hello.txt");

byte ] a="abcd".getBytes();

try{ FileOutputStream out=new FileOutputStream(f);

out.write(a);

out.close();

FileInputStream in=new FileInputStream(f);

byte ] tom= new byte3];

int m = in.read(tom,0,3);

System.out.println(m);

String s=new String(tom,0,3);

System.out.println(s);

m = in.read(tom,0,3);

System.out.println(m);

s=new String(tom,0,3);

System.out.println(s);

}

catch(IOException e) {}

}

}
}

">6.请说出下面中【代码】的输出结果

interface Com {
int add(int a, int b);

public static int get(int n) {
return n;
}

public default int see(int n) {
return n;
}

public default int look(int n) {
return n;
}
}

class A implements Com {
public int add(int a, int b) {
return a + b;
}

public int see(int n) {
return n + 1;
}
}

public class Main {
public static void main(String args]) {
A a = new A();
int m = a.add(12, 6);
int n = Com.get(12);
int t = a.see(6);
int q = a.look(6);
System.out.printf("%d:%d:%d:%d", m, n, t, q); //【代码】
}
}

7.

请说出E类中标注的【代码1.】~【代码4.】的输出结果()。(多个结果之间用#号隔开)。

Import java.io.*;

Public class E {

Public static void main(String args]) {

Int n=-1.;

File f =new File("hello.txt");

Byte ] a="abcd".getBytes();

Try{ FileOutputStream out=new FileOutputStream(f);

Out.write(a);

Out.close();

FileInputStream in=new FileInputStream(f);

Byte ] tom= new byte3.];

Int m = in.read(tom,0.,3.);

System.out.println(m); //【代码1.】

String s=new String(tom,0.,3.);

System.out.println(s); //【代码2.】

M = in.read(tom,0.,3.);

System.out.println(m); //【代码3.】

S=new String(tom,0.,3.);

System.out.println(s); //【代码4.】

}

Catch(IOException e) {}

}

try{

FileOutputStream out=new FileOutputStream(f) ;

out.write(a) ;

out.close () ;

FileInputStream in=new FileInputStream(f);byte ] tom= new byte100];

int m = in.read(tom) ;

String s=new String(tom,0, m) ;

System.out.printf("%d : %s" , m,s);

}catch (IOException e){}

}

">8.阅读以下程序，写出输出结果：

import java.io.*;

public class E{

public static void main(String args]){

int n=-1;

File f =new File("hello.txt") ;byte ] a="abcd".getBytes () ;

try{

FileOutputStream out=new FileOutputStream(f) ;

out.write(a) ;

out.close () ;

FileInputStream in=new FileInputStream(f);byte ] tom= new byte100];

int m = in.read(tom) ;

String s=new String(tom,0, m) ;

System.out.printf("%d : %s" , m,s);

}catch (IOException e){}

}

String str = list2.get(0);
}
}选项： A:对 B:错">9.以下代码是正确的。（）
package test;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class GenericTest1 {
public static void main(String[] args) {
List list2 = new ArrayList<>();
list2.add(new Date());
list2.add(new String("abc"));
String str = list2.get(0);
}
}选项： A:对 B:错

}
}
public class Benz extends Car {
public void run(){
System.out.println("奔驰在跑");
}
}
public static void main(String[] args) {
Car car = (Car)( new Benz() );
car. run();
} 选项： A、汽车在跑 B、奔驰在跑 C、无法编译 D、运行时将抛出异常">10.下面代码的运行结果是（）public class Car {
public void run(){
System.out.println("汽车在跑");
}
}
public class Benz extends Car {
public void run(){
System.out.println("奔驰在跑");
}
}
public static void main(String[] args) {
Car car = (Car)( new Benz() );
car. run();
} 选项： A、汽车在跑 B、奔驰在跑 C、无法编译 D、运行时将抛出异常

11.以下代码是正确的。（）
package test;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class GenericTest1 {
public static void main(String[] args) {
List list = new ArrayList();
list.add(new Date());
list.add(new Integer(1));
Date d = list.get(0);
}
}选项： A:对 B:错

12.读程序，以下哪个表达式返回值为true？ public class Sample{
long length;
public Sample(long l){ length = l; }
public static void main(String arg[]){
Sample s1, s2, s3;
s1 = new Sample(21L);
s2 = new Sample(21L);
s3 = s2;
long m = 21L;
}
} 选项： A、s1==s2 B、s2==s3 C、m==s1 D、s1.equals(m)

if (b instanceof C)
System.out.println("b is an instance of C");
}
}

class D extends C {
}

选项： A:

没有输出

B:

b is an instance of A

C:

b is an instance of C.

D:

输出b is an instance of A，然后是b is an instance of C.

">13.如下程序的运行结果为：（）。

interface A {
}

class C {
}

class B extends D implements A {
}

public class Test {
public static void main(String] args) {
B b = new B();
if (b instanceof A)
System.out.println("b is an instance of A");
if (b instanceof C)
System.out.println("b is an instance of C");
}
}

class D extends C {
}