COMP274 Week 1 Homework – Guaranteed 100% score
Week 1 Homework Assignment
Create a Word document containing the answers to all the problems given below.
1. What is the Java source filename extension? What is the Java bytecode filename extension?
2. Write a Java statement to display the string “The value is 100” to a user in a plain dialog box.
3. What is the command you would use to compile the file Addition.java?
4. What is the command you would use to execute the Addition class?
5. What does a Java class contain that identifies it as a Java application?
6. Write a Java statement that declares a constant called MAX which has a value of 1000.
7. How do C++ chars differ from Java chars?
8. Given a double variable called dval, write a single Java statement to prompt the user to enter the price of an item using JOptionPanes, convert the result and store it into dval.
9. Write one Java statement to display the string “The average is xxx” to the console, where the xxx displays the value from the double variable sum divided by 3. Make sure the value is displayed with 3 digits following the decimal point
10. Write one Java statement to create a string containing “The average is xxx” where the xxx contains the formatted value from the double variable sum divided by 3. Make sure the formatted string contains only 2 digits following the decimal point. Store the formatted string into a String variable called str.
11. Explain the difference between an object reference in Java and an object. Use an example to illustrate your answer.
12. Explain how objects are created in Java and how the memory used by objects is recovered. Compare this to object creation and destruction in C++.
13. Explain how primitive values like doubles are passed between functions in Java. How are string objects passed between functions in Java?
14. How are static methods different from non-static methods? How do you invoke a static method? Give an example of a static method.
15. Write an expression that returns a random value between 1 and 100. The values 1 and 100 must be included in the values that can be returned.
16. Write one Java statement that creates an array of 100 doubles.
17. Write one Java statement that creates an array of integers containing the multiples of 10 between 10 and 100, including 10 and 100.
18. Write one Java statement that would take an array A and copy its contents into array B. Assume that A and B already exist and that B is at least as large as A and that they are both of the same data type.
19. Write a Java method which takes an integer array parameter and locates the minimum value in the array and outputs that value using System.out.printf. Use an enhanced for loop to process the array. You only need one loop to do this!
20. Write a Java method which takes an integer array parameter and fills the array with random numbers between 1 and 1000, including 1 and 1000. Use a traditional for loop to process the array.
Create a Word document containing the answers to all the problems listed above.