Example 7-1 introduces randomization in the context of a simple program. It randomly combines parts of sentences to construct a story. This isn't a bioinformatics program, but I've found that it's an effective way to learn the basics of randomization. You will learn how to randomly select elements from arrays, which you'll apply in the future examples that mutate DNA.
The example declares a few arrays filled with parts of sentences, then randomizes their assembly into complete sentences. It's a trivial children's game; yet it teaches several programming points.
Example 7-1. Children's game with random numbers
#!/usr/bin/perl # Children's game, demonstrating primitive artificial intelligence, # using a random number generator to randomly select parts of sentences. use strict; use warnings; # Declare the variables my $count; my $input; my $number; my $sentence; my $story; # Here are the arrays of parts of sentences: my @nouns = ( 'Dad', 'TV', 'Mom', 'Groucho', 'Rebecca', 'Harpo', 'Robin Hood', 'Joe and Moe', ); my @verbs = ( 'ran to', 'giggled with', 'put hot sauce into the orange juice of', 'exploded', 'dissolved', 'sang stupid songs with', 'jumped with', ); my @prepositions = ( 'at the store', 'over the rainbow', 'just for the fun of it', 'at the beach', 'before dinner', 'in New York City', 'in a dream', 'around the world', ); # Seed the random number generator. # time|$$ combines the current time with the current process id # in a somewhat weak attempt ...