How to solve an indefinite integral in java?

How do I solve this Java Program?

• What is an Array and how does it work? An Array Program with a Client? Arrays with this Program? How do you do arrays in this Java Program? Write a class encapsulating the concept of converting integer grades to letter grades (A , B, C, D, or F), assuming grades are composed of a list of integers between 0 and 100. Write the following methods: • A constructor with just one parameter, the number of student; all grades can be randomly generated. • Accessor, mutator, toString(), and equals() methods. • A methods returning an array of chars corresponding to the integer grades (90 or above should be converted to A, 80 or above to B, 70 or above to C, 60 or above to D, and 59 or less to F). • A method returning the number of A’s. • A method returning an array of ints counting how many A’s, B’s, C’s, D’s, and F’s were received. Write a client class to test all the methods in your class. I am using Java Unlimited 3

• Answer:

  I won't provide exact answers, but the following should help you get started. For the class to handle converting number grades to letters, create your class with a method like: public static String getLetterGrade(final double grade) { // Initialize the letter grade to a value (let's default to a failing grade): String result = "F"; // then use conditional if/else statements to change the grade when appropriate: if (grade >= 90) { result = "A"; } else (if grade >= 80) { .. .. .. } return result; } For the constructor, this is just like the default constructor but with a parameter. You'll create like: public Foo(final int studentsToCreate) { // then include your logic to generate student data // Note: I'd recommend creating a "helper" method to generate a // single random student, then loop to call that method based // on the studentsToCreate variable using a "for" loop. } // Here is a helper method signature: private double generateGrade() { // Look up random number generation. If you want to create "double" // type values, create random grades from 0 - 1000 and divide // by 10. Ex. random is 897 and would become 89.7 as a double. } For the toString and equals methods, this is just overriding the ones inherited from the Object class. You can find samples of doing so online. For the method to get the number number of any letter grade, use a method like: public int getA() { // Then loop through the grade array. You could use your method to see what the letter // grade is and if the result equals "A" (remember String.equals("A") not String == "A"). } Ideally you'd use a more generic method like: public int getLetterGrade(final String grade) { // where "grade" is one of letter grades. } For your array, if you write the getLetterGrade(final String grade) method, you'll practically have all the logic for that method available to you. Just write as: public int[] getGradeArray() { // Position in array // A - 0 // B - 1 // C - 2 // D - 3 // F - 4 int[] gradeArray = new int[5]; // Then call per grade letter the getLetterGrade(...) method to populate your array. }