#! /usr/bin/perl

# These are examples of numeric values
$num1 = 78937294;
$num2 = 3424780;
print ("The sum of $num1 and $num2 is ", $num1+$num2, "\n");
print ("The difference of $num1 and $num2 is ", $num1-$num2, "\n\n");

# These are examples of perl strings
$name = "Debra Sue Bartlett";
$address = "272 Computer Science, Fort Collins, CO, 80523-1873";
$phone = "970-481-4191";
$sample_string = "a_aphabet_z";

#These are examples of string manipulations
# Print a string
print ("My name is $name \n");

# Select a subset of a string
# first parameter is the string name, second value is number of characters to skip, third value is number of characters to keep
$sample_substring = substr($name, 6, 3);
print ("The value of my sample substring is $sample_substring \n");

# Split a string into separate pieces
# first parameter is the character that separates each piece of the string, second  parameter is the string to be divided
@name_elements = split(/ /, $name);
print ("My first name is $name_elements[0], my middle name is $name_elements[1], my last name is $name_elements[2] \n");
@address_elements = split(/,/, $address);
print ("My building address is $address_elements[0], my city is $address_elements[1], my state is $address_elements[2], my zip code is $address_elements[3] \n");

# Search for a pattern in a string
if ($phone =~ /970/) 
   {print ("I have a local phone number \n\n")};
if ($phone !~ /970/) 
   {print ("I do not have a local phone number \n\n")};

# Search for a character at the beginning or end of a string
if ($sample_string =~ /z$/)
   {print ("I found z at the end of the string, $sample_string \n")};
if ($sample_string =~ /^a/)
   {print ("I found a at the beginning of the string, $sample_string \n\n")};

# Search for word and replace with a different word
$my_name = "Debra Sue Bartlett";
print ("My formal name is $my_name\n");
$my_name =~ s/Debra/Debbie/;
print ("My preferred name is $my_name\n");