 # Hard day at work! # Calculating average using a perl script

Ok here is the basic perl script for calculating average.

I assume you know how to run the script if you dont ( I will put up a tutorial later so for now dig around in other forms )

Perl Script for calculating average from another file

```#!/usr/bin/perl
#calculate averate from a file

use strict;

my \$total = 0;
my \$count =0;
while (my \$line = <>) {
\$total +=\$line;
\$count ++=;
}
print "Average = ", \$total / \$count, "\n";```

So the  explaniation for the above code is…

use strict; – allow to find simple mistakes

to find the \$average need to calculate

`my \$total`

and the total number of lines

`my \$count`

At the begining of the loop these values are 0.

therefore define the inital value

```my \$total  = 0;
my \$count =0;```

So now what you need to do this read each line andadd each value consequtively.

```while (my \$line = <>) {
\$total += \$line;
\$count ++=;
}
print "Average = ", \$total / \$count, "\n";```

Read the first line.  Then add then and the value read to the total inital value  of 0.

`   \$total = \$line + \$total`

calculate the total

`   \$count = \$count + 1`

calculate the total number of lines read
this can be written in short form as below

```   \$total += \$line;
\$count ++=;```

then go back in loop adding value conseutively until there are no more lines to read and then print the line

`print "Average = ", \$total / \$count, "\n";`

Hope this is clear I will put a anotated diagram up with more explanation later on.