JAVA TEACHER FOR STUDENTS
All the Java material you need as an IEB Information Technology (IT) student in South Africa.
Java Teacher does focus on IEB material for South African students doing grade 10, 11 and matric computer science but the resources in this website will assist first year IT university students as well.
How to use this site
Java Teacher is not a sequential Java textbook. Instead, it is a Java and SQL encyclopedia.
There are two ways to get help.
- On the right, you will find the topics sorted by grades.
- On the top right you will find a search bar where you can search by keywords eg class diagram, rounding, tracetables, debug etc
- This site is based on the Java by Example approach – less explanation and more examples. View or download the coded examples and study them, code them, run them, edit them, break them . . . this is how professional coders learn.
- There are two “Java by Example” textbooks that are a companion to this website. These textbooks offer an sequential learning experience grade by grade.
Java Teacher is passionately built and supported by Steve Eilertsen, an IT teacher at a private school in Johannesburg.
“This is my give-back strategy for IT learners who are passionate and gifted but do not have access to a suitable teacher.”
Online tutoring is available for matric learners in preperation for the PAT, Prelims and Finals for the remainder of 2026.
Gr 12 – Threads in Java
Understanding multithreading is difficult if you have never seen Java code with multiple threads. Threads have to be coded by the developer and is not taught at high school level. These two programs also use inheritance. Using Gogga is a useful way to demonstrate...
Gr11 – 12 Coding Dictionary
Coding dictionary for grade 11 and 12 containing 70 important coding terms
Gr 12 – Trace tables
Using a trace table to diagnose a problem with a pseudocode algorithm
Gr 12 – Search Array
In SQL there is an IN statement that looks for a value within a given list. Example. SELECT town FROM tblTowns WHERE town IN ('Johannesburg', 'Pretoria', 'Cape Town'); How does one code the same thing in Java when using a regular array? Here is a two-class OOP...
Gr 11 – String Handling Adv
With regard to String handling in Java. The Funworks Java textbook, Learning Unit 1 (Characters and Strings) has exercise 3.3 on page 19. In this exercise you are required to write Java String handling code that will . . . Ask the user for a word, phrase or sentence....
Gr11 12 – Data Validation
Data Validation Overview. V1 Validation first, followed by verification. Validation – does the data match the template? Example: The date template could be “yyyy-MM-dd” Verification – the data does match the template but is it valid? Example: “2026-14-13” matches the...
Gr11 12 – SQL database
It is easy to think that a database has some sort of logic, intelligence and self-awareness. It is does not. A database is like a suitcase of clothes. Some items "go with" other items but the clothes themselves do not understand their relationship with one another....
Gr12 – SQL. Random numbers
Random numbers with predictable starting and ending values eg 1 - 10, 1 - 100, 1 -1000In SQL we use the RND( ) function. Inside the round brackets goes the seed value (an integer value) Generating a random number requires a few steps. A) Generating a random number...
Gr 12 – SQL Adv
In grade 12 you need to be familiar with composite SQL statements (embedded / nested SQL statements). This means that two statements are joined together - the result set on one query is passed to the other. Therefore there are two SELECT / FROM statements joined...
Gr 12 – OOP Theory
In Java OOP we need to understand the terminology and the design concepts behind OOP. Here are two handouts, quite similar but one is a teaching document and the other is a study document. Click here for OOP theory handout Click here for OOP theory study notes One of...
Gr 12 – Inheritance Composite
In Java there is a swing away from inheritance, and it is possible that your practical exam papers may not have inheritance. Yes, there will still be four classes i.e. the UI class, the manager class and two template classes from which to create objects BUT the one...
Gr 10,11 – Comparing devices
In the theory exam you must be able to compare hardware digital devices catagory-by-category; but what are these catagories? In the document below Computer A is an Apple Mac laptop, Computer B is a Windows based laptop and Computer C is an Android based tablet....
Gr 10,11 – Application Suites
In the theory section we have to know application software. Applications do something; they achieve a task on behalf of the user. A computer with system software (an operating system like Ms Windows) will run, but it will not be very useful. Application software makes...
Gr 12 – Unicode
Converting characters or Strings to their Unicode values in Java. Once this is done the Unicode values of the characters can be added, subtracted, multiplied or divided. This is useful when wanting to establish whether a String login is valid or not. See output below....
Gr 11 – Rounding off
Being able to round a real number (double number) in Java off to a certain number of decimal places will be required in both the grade 11 and 12 practical exams. NOTE: When rounding off using these String based methods the accuacy of the origial number does not...