超星 - 输入输出流

单选题

Given the following statement, which statement will write "Calvin" to the file DiskFile.txt?给定以下语句，哪个语句将“Calvin”写入文件DiskFile.txt？PrintWriter diskOut = new PrintWriter("DiskFile.txt");

A. System.out.println(diskOut, "Calvin");
B. DiskFile.println("Calvin");
C. PrintWriter.println("Calvin");
D. diskOut.println("Calvin");

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单选题

When using the PrintWriter class, which of the following import statements would you write near the top of your program?使用PrintWriter类时，你需要在程序顶部附近写以下哪些语句？

A. import javax.swing.*;
B. import java.io.*;
C. import PrintWriter;
D. import java.file.*;

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单选题

Which of the following will open a file named MyFile.txt and allow you to append data to its existing contents?下列哪一个可以打开一个名为MyFile.txt的文件，并可以将数据追加到其现有内容中？

A. FileWriter fwriter = new FileWriter("MyFile.txt", true);PrintWriter outFile = new PrintWriter(fwriter);
B. FileWriter fwriter = new FileWriter("MyFile.txt");PrintWriter outFile = new PrintWriter(fwriter);
C. PrintWriter outfile = new PrintWriter("MyFile.txt", true);
D. PrintWriter outfile = new PrintWriter(true, "MyFile.txt");

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单选题

Assume that inputFile references a Scanner object that was used to open a file. Which of the following while loops shows the correct way to read data from t he file until the end of the file is reached?假设inputFile引用了Scanner对象。下列哪一项while循环显示了从文件读取数据直到到达文件结尾的正确方法？

A. while (inputFile != null){ … }
B. while (!inputFile.EOF){ … }
C. while (inputFile.hasNext()){ … }
D. while (inputFile.nextLine == " "){ … }

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单选题

A constructor is a method that:构造函数是哪样一种方法。

A. returns an object of the class. 返回类的一个对象
B. never receives any arguments. 从来没有收到任何参数
C. with the name ClassName.constructor. ClassName.constructor名称
D. performs initialization or setup operations. 执行初始化或设置操作

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单选题

A class’s responsibilities include:一个类的功能包括:

A. the things a class is responsible for doing 类负责做的事情
B. the things a class is responsible for knowing 一个类负责了解的东西
C. both A and BA和B都是
D. neither A or B

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单选题

This is a group of related classes.以下哪个是一组相关的类

A. archive 存档
B. package 包
C. collection 集合
D. attachment 附件

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单选题

Quite often you have to use this statement to make a group of classes available to a program.你必须使用此语句才能使一组类对程序可用。

A. import
B. use
C. link
D. assume 假设

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单选题

The scope of a public instance field is:公共实例字段的范围是:

A. only the class in which it is defined 只定义它的类
B. inside the class, but not inside any method 在类中，但不在任何方法中
C. inside the parentheses of a method header 在方法头的括号内
D. the instance methods and methods outside the class 实例方法和类之外的方法

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单选题

Instance methods do not have this key word in their headers:实例方法的头中没有以下哪个关键字:

A. public
B. static
C. private
D. protected

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