C from zero

Install a C compiler and VS Code, and run your first program on your own machine.

• Install C and VS Code 15 min

How a C program is built, how to print, and how to read the compiler's complaints.

• Hello, World! 6 min
• Printing with printf 9 min
• Errors and comments 8 min

Boxes in memory with a name and a type: int, double and char, and how to print each.

• Variables: named boxes 8 min
• int, double and char 10 min
• Changing values 9 min

Read numbers with scanf, and do maths the way C does it: integer division, remainders and casts.

• Reading input with scanf 10 min
• Division and remainder 10 min
• Mixing ints and decimals 9 min

Make the program choose: if, else if, conditions with && and ||, and switch.

• if and else 9 min
• else if, && and || 12 min
• switch 8 min

Repeat work with while and for, build patterns with nested loops, and stop early with break.

• while loops 10 min
• for loops 10 min
• Loops inside loops 11 min
• break, continue and do-while 10 min

Name a piece of work, give it inputs, get a result back, and let functions call themselves.

• Writing functions 11 min
• Copies and scope 9 min
• Recursion 12 min

Many values under one name: store, loop over, search, and lay them out in a grid.

• Arrays 11 min
• Finding things in an array 11 min
• 2D arrays 11 min

Text in C is an array of chars ending in '\0'. Read it, measure it, compare it and change it.

• Strings are char arrays 11 min
• string.h 10 min
• Processing text 12 min

Addresses, *, and how pointers let functions change your variables and walk through arrays.

• Addresses and pointers 12 min
• Pointers and functions 12 min
• Pointers and arrays 12 min

Ask for memory while the program runs with malloc, give it back with free, and avoid the classic memory bugs.

• malloc and free 12 min
• Memory bugs 11 min

Group related values into your own types, keep arrays of them, and pass them to functions.

• Your own types 11 min
• Arrays of structs 12 min

Sorting, binary search, counting and two pointers: the first tools of DSA, and why the faster one matters.

• Sorting 12 min
• Binary search 12 min
• Counting and two pointers 13 min