C Practice

Every lesson runs in your browser — write real code, press Run, and the tasks check themselves. Free, no account needed, with notes in English and Chinese.

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Lessons in this course

1. 01 Print a word
2. 02 Print another word
3. 03 Print a sentence
4. 04 Print with a !
5. 05 Print two lines
6. 06 Print three lines
7. 07 Print a number
8. 08 Add two numbers
9. 09 Subtract
10. 10 Multiply
11. 11 Remainder
12. 12 A number variable
13. 13 Add two variables
14. 14 Multiply two variables
15. 15 Your first function
16. 16 Is it positive?
17. 17 Cube a number
18. 18 The smaller one
19. 19 Square a number
20. 20 Sign of a number
21. 21 Largest of three
22. 22 Factorial
23. 23 Greatest common divisor
24. 24 Count the 1-bits
25. 25 Sum an array
26. 26 Swap two values
27. 27 String length
28. 28 Count a character
29. 29 Reverse in place
30. 30 Palindrome
31. 31 Bubble sort
32. 32 Points with a struct
33. 33 Binary search
34. 34 Parse an integer

Language reference

/know/reference/c