Web programming Units WEB1P and WEB2P

Programming prerequisite

Programming skills audit form (.DOC)

Reason for the prerequisite

A number of students have struggled with this unit in the past. The common characteristic of those students is lack of depth of experience in computer programming. It is not important to this course that students have used a particular programming language. Rather, it is important that they have come across and, crucially, understood some programming concepts that are common to the vast majority of languages.

If you're not sure whether you meet the prerequisite, but think you might, talk to the unit lecturer. If the unit lecturer advises you that you do not meet the prerequisite and you decide nevertheless to continue with the unit, you do so at your own risk. Some remedial help may be available, but staff time in practicals and elsewhere is prioritised towards developing unit-specific skills in students, rather than prerequisite ones.

Programming skills required

Essential concepts

Don't even think of doing the course unless you have used the following features in computer programs you have written:

• assignment statements (typically = or :=)
• output statements (e.g. print, write, printf, put)
• input statements (e.g. read, scanf, get)
• conditional statements (e.g. if-then, if-then-else, case, switch)
• iterative statements (loops) (e.g. while, repeat, for)
• subprograms (subroutines, procedures, functions; methods in an OO context)
• parameters to subprograms
• variables (and the distinction between local and global variables)
• types (e.g. integer, float, character, string)
• arrays
• records (structs in C/C++)
• pointers (or access types or reference types)

If you have done object-oriented (OO) programming (e.g. in Java or C++), and are familiar with concepts such objects, classes and object references (in Java, passing objects as parameters to methods) then you have probably covered the requirements for types, records and pointers above.

Also experience of using the following software tools is essential:

• editor
• compiler or interpreter

That requirement would be met if you had used an integrated development environment (IDE) that incorporates the above.

You must also be aware of what you need to do to:

• take a written specification of what the customer wants and turn it into a program
• test programs to see that they meet their specification

Desirable concepts

It is desirable that you understand the following concepts, even if you haven't developed programs using them:

• file handling (opening, closing, reading from and writing to files)
• data structures (combinations of arrays, records and pointers to construct data representing complex entities) and which ones you would choose to use in given circumstances
• object-oriented programming (classes, objects, methods) and the idea of structuring your program as a set of semi-independent and hopefully reusable components
• issues of program modularity (e.g. packages, separate compilation, separate header files, include files) and why you would choose to split your program up in a certain way
• exceptions (error reporting and propagation)
• concurrency (or distributed systems programming) and the issues associated with more than one program (or part of a program) running at the same time
• breakpoint debugging

You must be prepared to do some background reading to bring yourself up to speed with these topics if you have not studied them before.

Languages

Most students doing this unit in the past have experience of programming in at least one of C, C++ or Java. Experience in languages such as Pascal, Ada or Visual Basic is also valuable. Students whose experience has been in other languages should talk to the unit lecturer to make sure he is aware of their background.

Previous experience in Perl is not a bar to doing the course. However, students who have done a significant amount of CGI programming may be eligible for APEL (accreditation of prior experience and learning) for the unit.

Practical test

As a practical test of whether or not you meet the prerequisite, attempt the following programming exercise using any programming language of your choice:

• Write a procedure that reverses the contents of an array of characters (or string) passed as its parameter.
• Write a program that reads in a sequence of lines of text. As each line is read in, store each character in an array or string. Call the procedure to reverse the characters in the line, and then print out the modified array. Finally print out the number of lines and the total number of characters that were read in, in the format "1 line; 27 characters". The words "line" and "character" must be made plural (with an "s" on the end!) if the number is anything other than 1.

If you've completed the exercise successfully, and ensured that your program meets the above specification, you are able to do the unit.