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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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");
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 == " "){ … }
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
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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