Purdue CS 24000: Programming in C
CS 24000 teaches C to students who already know Java from CS 18000 (pointers, memory management, structs, dynamic allocation, and the machine-level view of data) as preparation for the systems half of the Purdue CS core. Homework is programming-heavy and exams test C semantics in detail.
Fennie is independent and not affiliated with Purdue University. This is an unofficial study guide.
What makes it hard
Pointers are the famous wall: after Java's managed memory, manual allocation, pointer arithmetic, and segfaults demand a mental model of memory most students have never needed. The compiler stops protecting you, since code that compiles can still corrupt memory silently, so debugging skill and discipline matter as much as understanding the syntax.
What you'll cover
- • C syntax and the compilation model
- • Pointers and pointer arithmetic
- • Arrays, strings, and memory layout
- • Structs and typedefs
- • Dynamic memory allocation
- • File I/O and debugging tools
The CS 24000 study guide
How to study for Purdue CS 24000, step by step.
- 1
Draw memory for every pointer operation
The students who survive CS 24000 are the ones who diagram: boxes for variables, arrows for pointers, before-and-after for every assignment. Make drawing memory your default until you can run pointer code in your head.
- 2
Embrace the segfault as information
Learn gdb and valgrind early; they turn 'it crashed' into 'this line dereferenced a freed pointer.' Debugging tooling is the difference between two-hour and two-day homework sessions in this course.
- 3
Translate Java idioms into C deliberately
For each thing you know in Java (objects, arrays, strings), work out what it becomes in C and what the machine is doing underneath. The course's whole point is replacing Java's abstractions with the real memory picture.
- 4
Hand-trace allocation and freeing before exams
Exam questions present C code and ask what it prints, what leaks, or what breaks. Practice tracing malloc/free lifecycles and pointer arithmetic on paper, because that's the exact format you'll face.
Today
Today's CS 24000 plan
What a Fennie Daily Plan looks like for CS 24000. Yours is built from your own syllabus and adapts every day to your deadlines and progress.
First plan free, no card required. Fennie is independent and unaffiliated with your school.
FAQ
Is CS 24000 at Purdue hard?
It's a real step up from CS 18000 because C removes Java's safety net: pointers, manual memory, and silent corruption. Students who draw memory diagrams and learn the debugging tools handle it; students who code by trial and error lose entire weekends to segfaults.
Why is C so much harder than Java?
Java manages memory for you; C makes you do it. You're responsible for allocation, freeing, and pointer correctness, and mistakes don't throw clean exceptions; they corrupt memory or crash later somewhere else. The fix is building an explicit mental model of memory, which is exactly what the course exists to teach.
How does CS 24000 prepare me for CS 25200?
Systems Programming assumes C fluency completely; its large projects are written in C under deadline pressure. The pointer and memory skills you build here are load-bearing for the hardest projects in the Purdue core, so genuine comfort with C is worth more than the grade.
More Purdue courses
CS 18000: Problem Solving and Object-Oriented Programming
CS 18000, universally called CS 180, is Purdue's first course for CS majors: object-oriented programming in Java, from control flow and methods through classes, inheritance, interfaces, exceptions, file I/O, and concurrency basics. It's the famous freshman gauntlet that sets the tone for the entire Purdue CS core, with labs, projects, and exams that include writing real code.
CS 18200: Foundations of Computer Science
CS 18200 is Purdue's discrete math course for CS majors (logic, proofs, sets, functions, induction, counting, graphs, and basic complexity), usually taken alongside or right after CS 18000. It's the course where CS stops being programming and starts being mathematics.
CS 25000: Computer Architecture
CS 25000 covers how computers actually work, from transistors and logic gates up through combinational and sequential circuits, datapaths, assembly language, and memory hierarchy. It's one of the two sophomore-core courses (with CS 25100) that Purdue CS students take after the freshman sequence.
CS 25100: Data Structures and Algorithms
CS 25100 is Purdue's data structures and algorithms course (lists, trees, heaps, hash tables, graphs, sorting, and algorithm analysis) and the most notorious course in the CS core. It gates the upper-division CS curriculum and its exams have a campus-wide reputation for difficulty.