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创建和测试学生对象。
public class Main /** from * NowJava.com **/ { public static void main(String[] args) { Student account1 = new Student("James Bond", 93.5); Student account2 = new Student("Michael Bates", 72.75); System.out.printf("%s's letter grade is: %s%n", account1.getName(), account1.getLetterGrade()); System.out.printf("%s's letter grade is: %s%n", account2.getName(), account2.getLetterGrade()); } } class Student { private String name; private double average; // from N o w J a v a . c o m // constructor initializes instance variables public Student(String name, double average) { this.name = name; // validate that average is > 0.0 and <= 100.0; otherwise, // keep instance variable average's default value (0.0) if (average > 0.0) { if (average <= 100.0){ this.average = average; // assign to instance variable } } } // sets the Student's name public void setName(String name) { this.name = name; } // retrieves the Student's name public String getName() { return name; } // sets the Student's average public void setAverage(double average) { // validate that average is > 0.0 and <= 100.0; otherwise, // keep instance variable average's current value if (average > 0.0) { if (average <= 100.0){ this.average = average; // assign to instance variable } } } // retrieves the Student's average public double getAverage() { return average; } // determines and returns the Student's letter grade public String getLetterGrade() { String letterGrade = ""; // initialized to empty String if (average >= 90.0) letterGrade =