Count the frequency of base G in a given DNA sequence

Nishi Singh — Tue, 10 May 2016 11:38:32 -0500

#!/usr/bin/perl
use strict;
use warnings;

my $DNA = "GATTACACAT";

#initialize $countG and $currentPos
my $countG = 0;
my $currentPos = 0;

#calculate the length of $DNA
my $DNAlength = length($DNA);

#for each letter in the sequence check if it is the base G
#if 'yes' increment $countG
while($currentPos < $DNAlength){
	my $base = substr($DNA,$currentPos,1);
	if($base eq "G"){
		$countG++;
	}
	$currentPos++;
} #end of while loop

#print out the number of Gs
print "There are $countG G bases\n";

BOL: Count the frequency of base G in a given DNA sequence

Count the frequency of base G in a given DNA sequence