Programming constitutes a key part of any Computer Science Course. The IB uses two “languages”, one for Paper 1 and another one for Paper 2 (Option D only). The Paper 1 language is called Pseudocode and is perhaps more formal than what you would expect. For the external assessment of Option D Java is the prescribed language.
As well as programming in a real programming language throughout the course, such as Java, you will also be expected to learn how to write in pseudocode. Pseudocode is a simplified language, and an alternative way to represent a program in many different languages. If you can understand a program written in pseudocode, you should be able to then re-write that program in your choice of language, and vice versa.
The programming questions in Paper 1 will be written in Pseudocode. Your answers to those questions should also be written in Psuedocode.
The IB supply two documents that offer further reading and examples, one of which is supplied during the exams as a guide.
The IBO publishes specific guidelines (called the Java Examination Tool Subset). The JETS document contains the commands, symbols and constructs used in examination questions relating to the OOP option.