Pseudo-random numbers in C:

Introduction:

In Ancient Greek, the adjective:

ψευδής[1].

or, when transliterated:

‘pseudḗs’

means:

‘lying,’ ‘false,’ ‘fictitious,’ ‘sham’[2].

A classical computer is a deterministic machine, and, in and of itself, cannot generate a truly random number. A classical computer, in and of itself, can only generate a pseudo-random number.[3].

A pseudo-random number is not a true random number – its having been generated through a deterministic process – however it is considered, from a human perspective, random enough for most purposes.

Body:

In C, we use the:

rand()

function so as to generate a pseudo-random integer. Prior to our invoking the:

rand()

function, though, we must first:

include

the:

stdlib.h

header file.

Thus:

#include <stdlib.h>

The code needed so as to compile a simple pseudo-random number generator is as follows:

Snippet 1: The code needed so as to compile a simple pseudo-random number generator.

The code, as found in Snippet 1, when compiled into an executable, outputs the following program:

Figure 1: The program outputted should the code in Snippet 1 be compiled and executed.

As we may observe, the program as depicted in Figure 1: produces the pseudo-random integers:

and:

18467

Conclusion:

Should one know how to generate pseudo-random numbers in the C programming language, then he/she knows how to generate pseudo-random numbers in C# and C++, which are two languages that are employed so as to code modern videogames in the Unity^TM and Unreal^TM engines/IDEs, respectively.

I once heard it said that it is the random-number generator that makes videogames fun, as it can make the enemies and hazards that the player must face unpredictable. Being able to generate pseudo-random numbers in C-derived languages is a must-have skill for a professional game-developer.

[1]. ψευδής, ψευδής, ψευδές or ‘pseudḗs, pseudḗs, pseudés,’ 1^st-and-2^nd-declension adjective.

[2]. James Morwood, John Taylor (ed.s) Oxford University Press. Pocket Oxford Classical Greek Dictionary . Oxford. 2002. p. 352

[3]. For a classical computer to obtain a true random number, it must go outside of itself. The website, random.org obtains true random numbers by deriving them from the measurement of atmospheric noise.

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