C

Simple C examples

Basically some popular tiny challenges that people struggle with when starting to learn C. Can be described as 'didactic examples'.

evaluationOrder.c

The order how parameters are evaluated is implementation-specific. This example(s) show(s=, how the evaluation-Order is not always trivial/what you expect

ArraySerialisationPtrArithmetics.c

Short example showing how to get all members of a 2d (or Nd..) array with ptr-arithmetics rather than by looping

ptrToPtrFree.c

Example shows how to free (and securely free) a List-struct by freeing its pointer, which is handed over by call-by-reference, thus a pointer to a pointer.

callbackFuncPtr.c

Shows how to utilize function-pointers to get callback-functionality in C

functionPtr.c

Implements a map-function that calls functions via function-pointers on an array, explains how function-pointers are used and what they are good for

recursiveMultiply.c

How to implement multiplication of two numbers using recursion

linkedList.c

Example-Implementation of a singly linkedList in c existing on the heap. supported functions: LinkedList* init_list(); void insert_end(LinkedList *list, int key, char string[]); void insert_beginning(LinkedList *list, int key, char string[]); int remove_end(LinkedList *list); int remove_beginning(LinkedList *list); int print_list(LinkedList *list); void free_list(LinkedList *list); char * get_string(LinkedList *list, int key);

matrix.c

example application for an simple Matrix-struct and a function that evaluates if a given Matrix is symetric

pyramid.c

asks for number of rows, prints all odd numbers in a pyramid

bitToggle.c

example of how to toggle, invert, set, get bits in a bitfield

hexDump.c

cool tool to analyze the memory of string in c, very didactic :)

intHexBin.c

tool that helps in understanding the different representations of values: dez, hex, bin

retCharPtr.c

This example shows why in C one can't simply return an dynamicaly long string from a function it explains call-by-reference, dynamical allocation with malloc, and defunct returning utilizing the popular local-scope mistake

intToBin.c

Simple reading of programm argument, parsing it from char ptr to int using itoa(..), then converting it to a binary-string with a function by call-by-reference.

arrSumPtrArithmetic.c

Simple example showing how to sum up a array 1) using 'normal' array indexing and 2) using pointer arithmetic

callByReference.c

Simple example showing call-by-reference

callByRefSwap.c

Simple example showing how to swap two variables using call-by-reference

heapMemVsStackMem.c

Example showing what happens if you incorrectly malloc memory. After a function exits, the Stack is GONE, and so are values allocated in it.

stupidLinkedList.c

A very simple linked list example

structOffset.c

Shows with pointer arithmetic how the byte-offsets of a struct work in C

arrayType.c

how to define and use a typedef "Array" which knows its size and does bounds-checking when accessing it. It is allocated on the heap and freed after usage. Good example of call-by-reference, Heap-memory allocation and how to use types in a effective manner.

shlemielThePainter.c

this example was motivated by this ancient(2001) blogpost by Joel Spolsky https://www.joelonsoftware.com/2001/12/11/back-to-basics/

bitField.c

What and how to do something using bitfields