Oliver Fuchs wrote:
Hi,
Hello,
I am a very beginner to perl so may be this question is stupid or too low
leveled then please ignore.
I tried to wright a little calculator in perl - nothing difficult - very
simple:
#!/usr/bin/perl -w
print "First value: ";
chomp ($value1=<STDIN>);
print "Second value: ";
chomp ($value2=<STDIN>);
print "What operator (+ - * /)? ";
chomp ($operator=<STDIN>);
if ($operator eq "+") {
print ($value1 + $value2, "\n");
} elsif ($operator eq "-") {
print ($value1 - $value2, "\n");
} elsif ($operator eq "*") {
print ($value1 * $value2, "\n");
} elsif ($operator eq "/") {
print ($value1 / $value2, "\n");
} else {
print "Keep it simple \n";
}
You could do something like this:
#!/usr/bin/perl -w
use strict;
my %calc = (
'+' => sub { return $_[0] + $_[1] },
'-' => sub { return $_[0] - $_[1] },
'*' => sub { return $_[0] * $_[1] },
'/' => sub { return $_[0] / $_[1] },
);
print 'First value: ';
chomp( my $value1 = <STDIN> );
print 'Second value: ';
chomp( my $value2 = <STDIN> );
print 'What operator (+ - * /)? ';
chomp( my $operator = <STDIN> );
if ( exists $calc{ $operator } ) {
print $calc{ $operator }->( $value1, $value2 ), "\n";
}
else {
print "The operator '$operator' does not exist.\n";
}
Originell I tried to put the operator from <STDIN> directly to print like
this:
[...]
print "First value: ";
chomp ($value1=<STDIN>;
print "Second Value: ";
chomp ($value2=<STDIN>;
print "Operator: ";
chomp ($value3=<STDIN>;
print ($value1 $value3 $value2, "\n");
But that was malfaunctioning. Is there a way to put the STDIN for the
operator directly in the print line or do I always have to keep it that long
winded?
You could always use the eval() function:
perldoc -f eval
John
--
use Perl;
program
fulfillment
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