Advanced C Programming

About this course

Systems & Memory Control: pointers, pointer arithmetic and double pointers, the heap (malloc/realloc/free), structs and linked lists, bitwise hardware masks, and file I/O through to function-pointer dispatch - four modules, one Compiler Quest per topic.

This is a 6-week short course - enough depth to build real projects and a portfolio piece, without a long commitment. Learn online at your own pace. Practice the concepts with the listed assessments.

What's included

• Self-paced lessons and practice (12 estimated hours).
• Hands-on coding quests you solve inside the EchoLens browser compiler - nothing to install.
• Gems, stages and a leaderboard that keep you moving instead of grade anxiety.
• A verified certificate with a scannable QR code, ready to share on LinkedIn, when you satisfy the course requirements.
• Completely free - no fee, just create an account and start.

What you will learn

Course outline - level by level

12 leveles, each with hands-on quests you clear in the portal.

• Level 1. Pointers & Dereferencing - Real-life analogy: Think of a treasure map containing coordinates written on a parchment. The parchment itself is not the chest of gold - it merely holds the geographical latitude and longitude (the address) of where the gold is buried. Opening the chest at those coordinates is dereferencing. A pointer is a special variable whose value is the physical hexadecimal memory address of another variable in RAM. Using the reference operator & extracts the memory location, while the dereference operator * accesses or modifies the data stored directly at that target address, unlocking low-level memory mutation across function scopes.
• Level 2. Pointer Arithmetic - Real-life analogy: Think of a street where houses are numbered in steps of 4 meters. If you are standing at House 0 and take "1 step forward," you don't advance 1 millimeter - you jump exactly 4 meters down the sidewalk to House 1. In C, an array name decays into a constant pointer to its first element (arr == &arr[0]). Adding 1 to a pointer (ptr + 1) does not add 1 byte - it advances the address by sizeof(type) bytes (e.g. 4 bytes for an int). Therefore *(arr + i) is mathematically and mechanically identical to arr[i].
• Level 3. Double Pointers (**ptr) - Real-life analogy: If a manager wants to reassign which employee leads a project, they don't just change the employee's title - they update the CEO's project-assignment ledger (a pointer to a pointer) to point to a completely different lead engineer. Because C does not have native pass-by-reference syntax, pointers allow functions to mutate variables in the caller's stack frame. When a function needs to allocate or modify the pointer itself (such as altering where a buffer points), a double pointer (type**) is passed to allow indirection across two stack levels.
• Level 4. malloc() & calloc() - Real-life analogy: Stack memory is like booking a hotel room for a fixed 24 hours (automatic checkout upon leaving). Heap allocation is buying commercial land on demand - you can request any custom acreage you need at runtime, but you must construct and manage it manually. Stack memory has a fixed size and automatic lifetime tied to function scope. malloc(size_t) requests contiguous raw bytes from the Heap at runtime and returns a void* pointer to the base address. calloc(num, size) allocates memory and initializes every single bit to zero, preventing garbage value issues.
• Level 5. Buffer Resizing (realloc) - Real-life analogy: Think of expanding a modular warehouse. If adjacent land is empty, the builder simply moves the back wall outward. If adjacent land is occupied by neighbors, the builder purchases an entirely new large plot across town, moves all your inventory there, and tears down the old building. realloc(ptr, new_size) expands or shrinks an existing heap allocation. If contiguous space is available immediately following the current block, it expands in-place. Otherwise, it allocates a new block elsewhere, copies the existing data over automatically, frees the old block, and returns the new pointer.
• Level 6. Memory Leaks & free() - Real-life analogy: Renting an apartment key, making a copy, throwing the original lease in the incinerator, and leaving the water running. You can never return the key (a memory leak), and trying to open the door after the building is demolished (a dangling pointer) leads to disaster. Heap allocations persist until explicitly released. Failing to call free(ptr) causes memory leaks that consume system RAM over time. After freeing memory, the pointer becomes a dangling pointer - dereferencing it invokes undefined behavior. Always set pointers to NULL immediately after freeing.
• Level 7. struct & typedef - Real-life analogy: Think of a composite passport document. It binds different types of identity records - name (string), age (int), and visa validity (char) - into one cohesive official booklet that can be handled as a single unit. The struct keyword packages heterogeneous data types into a contiguous composite type. Compilers automatically insert invisible byte alignment padding to keep fields aligned to 4-byte or 8-byte word boundaries for CPU performance. The typedef keyword creates clean type aliases for concise syntax.
• Level 8. Linked Lists - Real-life analogy: Think of a treasure hunt where every clue card contains two things: a clue message (the data payload) and a written GPS coordinate pointing to the location of the next card in the forest (the next pointer). A self-referential struct contains a member pointer that points to another struct of its own type (struct Node *next;). Unlike contiguous arrays, linked lists allocate elements non-contiguously on the heap, linking nodes dynamically through pointer chains. This enables O(1) insertions without memory reallocations.
• Level 9. Bitwise Operations & Masks - Real-life analogy: Think of an electrical control panel with 8 physical toggle switches. Rather than building 8 separate giant power boxes, a single master byte controls all 8 switches. Flipping Switch #3 up is a bitwise OR operation. Bitwise operators manipulate raw binary bits inside an integer: AND (&), OR (|), XOR (^), NOT (~), Left Shift (<<), and Right Shift (>>). Bit masks allow programmers to set, clear, and toggle individual hardware flags in microcontroller registers without altering neighboring bits.
• Level 10. Stream File I/O - Real-life analogy: Opening a file stream is like connecting a pipeline to an underground storage silo. The valve is opened with a mode key ("r" for read, "w" for write). If you forget to close the valve (fclose), fuel leaks into the system buffer. C manages persistent disk files using a buffered stream handled by the FILE* control structure. Programs must open streams with fopen(), perform formatted disk reads/writes via fscanf() and fprintf(), and flush/release kernel handles using fclose() to prevent resource locks.
• Level 11. Binary Block I/O - Real-life analogy: Writing plain text to disk is like translating a document word-by-word into handwriting. Binary block I/O is taking a high-speed polaroid photograph of the exact physical RAM memory block and dumping it directly onto the disk in milliseconds. Text files convert internal numbers into ASCII strings, which is slow and space-inefficient. Binary I/O via fwrite() and fread() streams raw contiguous byte buffers directly between RAM and disk storage, preserving exact binary representations of structs and large arrays with zero translation overhead.
• Level 12. Function Pointers & Callbacks - Real-life analogy: Think of a universal power drill with quick-swap bit chucks. The drill handle (the host execution engine) doesn't care whether you plug in a screwdriver bit or a sanding bit - it simply invokes whatever tool bit is slotted in at runtime. In C, executable machine code also resides in memory. A function's name points to the memory address of its entry instruction. A function pointer (int (*func_ptr)(int, int)) stores this executable address, enabling dynamic callback routines, event listeners, and pluggable dispatch tables like the standard library's qsort().

How you submit: Coding quests solved in the built-in EchoLens compiler.

Who it's for

Advanced C Programming suits learners at a beginner to intermediate level who want a practical, project-based route into Advanced C Programming. You need only a browser and an internet connection - all coding runs inside the EchoLens compiler, so there is nothing to set up.

Certificate

Pass every required assessment at its stated threshold to earn your verified certificate. Optional practice and watching videos do not determine eligibility. Anyone can scan its QR code to verify it on our site. You can add it to your CV or share it to LinkedIn in one click.