a) What is the difference between StringBuilder and String? b) Which of the following classes are Immutable: Integer, Short, Byte, String, Boolean, Flo Character, BigInteger, StringBuilder, StringBuffer? c) Can you sort an array of Strings, Dates and Integers using the same method? If so, provide example. d) Create a new Java file in Eclipse. Perform the following operations: 1. Create a new StringBuilder from the String "Prepare for your Midterm Exam". 2. Check the capacity of the StringBuilder if it's empty. 3. Find the index of the letter 'y'. 4. Delete a substring from the starting index till this index (of 'y'). 5. Insert a string "Good luck on " at the beginning of the StringBuilder. 6. Append '!' to it. 7. Print your StringBuilder to Console. 8. Attach the screenshot of code and output to the PDF file.

What is the purpose of the sandbox model?

Use ruby on rails and on command line. Add the following parts to your student management system. Prefix: prefix, has many courses. Course: Belongs to a prefix, number, name, has many sections. Semester: semester ("Spring", "Summer", "Fall", …), year, has many sections. Section: CRN, belongs to a course, belongs to a semester. Clean up the browser display for the following. Foreign keys are not displayed, but reasonable text is. There is a drop-downs for prefixes when creating courses, and drop-downs for course and semester when creating a section. A course displays all the sections. A semester displays all the sections. Something reasonable is displayed if a null is detected.

Discuss the role of usability testing in interface development. What are the steps involved in conducting a usability test, and how can the results be used to improve the interface?

Compare three IDEs for development using Java- The best interfaces- Easier to handle- Installation method

Show me a nice UI. Distinguish between GUIs, NUIs, and CLIs.

Java GUI frameworks: AWT and JavaFX. List 5 similarities and  5 differences between the frameworks of AWT and JavaFX,Mainly  target PlatformComponentsLayoutsPackagesMediaHelper Classes   thanks

Explain the concept of the Aqua interface and its evolution.