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Introduction to C and Memory Management

COMP281 Lectures

Hello, world!

A “Hello, world!” program would look something like so:

#include <stdio.h>
int main(void) {
	printf("Hello, World!\n");
	return 0;
}

You can then compile and run with the following commands:

$ gcc hello.c
$ ./a.out
Hello, world!

Properties of C

Advantages

  • C is almost a portable assembly language. It is as close to the machine as possible while it is almost universally available for existing processor architectures.
  • Arbitrary memory address access and pointer arithmetic.
  • Deterministic usage of resources that fit for resource-limited systems.
  • C has a very small runtime. The memory footprint for its code is smaller than for most other languages.
  • Many implementations of new algorithms in books are first (or only) made available in C by their authors.
  • C is an old and widespread language – it’s easy to find all kinds of algorithms written in C.

Disadvantages

  • No concept of Object Oriented Programming (OOP).
  • No concept of namespace.
  • No constructor or destructor.
  • Difficult to debug.
  • Compilers cannot handle exceptions (run-time errors).
  • No strict data type checking:
    • An integer value can be passed for floating datatype.