IB CS 2027

Computer Science

Learn to program for the new IB course, one small step at a time, then practise with exam-style questions that are marked as you go.

Computer Science · start here · lesson 1.1

Print one line

Part 1: Programs that talkA short reading2 questions

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Java answers can't run on ExamSpine yet. You can still read Java, trace it, and put an answer's lines in order.

Part 1: Programs that talk

0 of 12 lessons done.

1.1Print one linestart here
1.2Statements run top to bottom
1.3Read a line and print it back
1.4Join text with +
1.5A variable holds one value; assigning again replaces it
1.6Read several lines, use them in any order
1.7Four basic types
1.8Turn typed text into a number

All 12 lessons in Part 1

Your programming path

Short programming lessons for the new IB Computer Science course, in Python or Java. 69 lessons ready so far. The theory side of the course (hardware, networks, databases, machine learning and more) is not written yet.

Number	Part	Done
1	Programs that talk	0 / 12
2	Decisions	0 / 10
3	Repetition	0 / 10
4	Functions	0 / 8
5	Text, lists, stacks and queues18 of 19 lessons written so far	0 / 18
6	Errors, testing and files6 of 14 lessons written so far	0 / 6
7	Algorithms3 of 13 lessons written so far	0 / 3
8	One class2 of 14 lessons written so far	0 / 2

Parts 9 to 10 are not written yet: Several classes (HL only), Abstract data types (HL only).

How a lesson works

1
Read
Most lessons start with a short reading on one idea, with examples in Python and Java.
2
Practise
Write the code yourself, straight away, on the same page.
3
Check
Code answers are run against tests, and you see what each one found.Trace tables and lines put in order are checked for you, and you can compare your code with a worked solution.

Try it: follow the code line by line

Each row is one step: the line that runs, the values of v and total after it, and anything it prints.

trace.py

1total = 0
2for v in [3, 5, 2]:
3 total = total + v
4print(total)

linevtotaloutput

every spine trace is made by running the code

Exam-style programming practice

Question bank
Exam-style questions by topic and difficulty.
Exam mode
Write code as you would on paper, without running it.
Trace tables
Follow code by hand. Every row is marked.