Question

Rewrite calcs.pl to use subroutines. The program should prompt the user for 2 numbers, take those 2 numbers in and pass them to the 5 different subroutines for each operator example. Each of the subroutines should pass the result back out of the subroutine to the main routine for printing to the user.

Answer 1

• I assumed that the program to be rewritten is calculator program for basic arithmetic operators in Perl.
• The basic arithmetic operators were not mentioned so i did the solution for six operators namely addition, subtraction, multiplication, division, power and remainder operators in Perl.
• In the code written below, the symbol "#" means a comment .

The code is as follows :-

use warnings;

#Here are the subroutines for each operator.

sub Add($$){

    my ($a, $b) = @_;

    my $c = $a + $b;

    return ($c);

}

sub Subtract($$){

    my($a, $b) = @_;

    my $c = $a - $b;

    return($c);

}

sub Multiply($$){

    my($a, $b) = @_;

    my $c = $a * $b;

    return ($c);

}

sub Div($$){

    my ($a, $b) = @_;

    my $c = $a / $b;

    return ($c);

}

sub Remainder($$){

    my ($a, $b) = @_;

    my $c = $a % $b;

    return ($c);

}

sub Pow($$){

    my ($a, $b) = @_;

    my $c = $a ** $b;

    return ($c);

}

#The main routine starts here.

print "Enter two numbers for calculation \n";

#Taking user input.

my $input1 = <>;

my $input2 = <>;

#Calling subroutines and storing corresponding results for printing.

my $add_result = Add($input1, $input2);
my $sub_result = Subtract($input1, $input2);
my $mul_result = Multiply($input1, $input2);
my $div_result = Div($input1, $input2);
my $pow_result = Pow($input1, $input2);
my $remainder = Remainder($input1, $input2);

#Printing the results obtained from the subroutines.

print "The result of addition is = $add_result \n";
print "The result of subtraction is = $sub_result \n";
print "The result of multiplication is = $mul_result \n";
print "The result of division is = $div_result \n";
print "The result of power operation is = $pow_result \n";
print "The result of remainder operation is = $remainder \n";