Hello thevoid,

You're fairly close - you just have the syntax a bit off.

The general structure is this:

if ( condition ){
    # code
}
elsif ( condition ){
    # code
}
else {
    # default case, in case no conditions match
}
[download]

So your code should look like this:

#!/usr/bin/perl
#hash.plx
use warnings;
use strict;
my %phnums = ( derrick => '07786255633',
               juan    => '07798685311',
               kevin   => '07740647707',
);

print "Enter a name : ";
my $name = <STDIN>;
chomp ($name);

if ($name =~ /^derrick\b/i) {
    print $phnums{"derrick"};
}
elsif ($name =~ /^juan\b/i) {
         print $phnums{"juan"};
} 
else {
        print $phnums{"kevin"};
}
[download]

Note, if you enter "fred", you'll see Kevin's number. So you might instead want:

#!/usr/bin/perl
#hash.plx
use warnings;
use strict;
my %phnums = ( derrick => '07786255633',
               juan    => '07798685311',
               kevin   => '07740647707',
);

print "Enter a name : ";
my $name = <STDIN>;
chomp ($name);

if ($name =~ /^derrick\b/i) {
    print $phnums{"derrick"};
}
elsif ($name =~ /^juan\b/i) {
         print $phnums{"juan"};
} 
elsif ($name =~ /^kevin\b/i) { 
        print $phnums{"kevin"};
}
else {
        print "Name not found.";
}
[download]

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)
[download]

if ($name =~ /^derrick\b/i) 
{
    print $phnums{"derrick"};
} 
elsif ($name =~ /^juan\b/i) 
{
    print $phnums{"juan"};
} 
elsif ($name =~ /^kevin\b/i) 
{ 
    print $phnums{"kevin"};
}
else
{
    print "No such person!\n";
};
[download]

...
chomp ($name);
if (exists $phnums{$name}) {
  print $phnums{$name};
} else {
  print "Name $name does not exists in the hash.";
}
[download]

I was operating under the assumption that a user could enter "Kevin Johnson" and still get the value for $phnums{'kevin'} - i.e. more than what might be used as the explicit hash key. Possibly a poor assumption, but I couldn't think of a better reason for using regexen in the OP's code :-)

I recently ran across a hash setup as a dispatch table where most values were well defined, but some could match a variety - these were handled (in a generalized manner) like so:

if( exists $hash{$key} ){
    &$hash{$key};
}
elsif( $key =~ /phrase/ ){
    # several could match but all required the same action
    &$hash{'some_action'};
}
else {
    &$hash{'default_action'};
}
[download]



--chargrill

---

s**lil*;  $*=join'',sort split q**;  s;.*;grr; &&s+(.(.)).+$2$1+; $; =
qq-$_-;s,.*,ahc,;$,.=chop for split q,,,reverse;print for($,,$;,$*,$/)
[download]

I was operating under the assumption that a user could enter "Kevin Johnson" and still get the value for $phnums{'kevin'} - i.e. more than what might be used as the explicit hash key.

You're right, that was the idea :-) Thanks for the alternative code.

Ah, nice one. I hadn't really covered exists yet but had seen it mentioned, that makes sense.

An if ...elsif ... elsif ... else statement looks like this:

if (condition1)
   { code block }
elsif (condition2)
   { code block }
elsif (condition3)
   { code block }
else
   { code block }
[download]

chomp (my $name = <STDIN>);

if ($name =~ /^derrick\b/i)
{
    print $phnums{"derrick"};
}
elsif ($name =~ /^juan\b/i) {
         print $phnums{"juan"};
} 
elsif ($name =~ /^kevin\b/i) {
        print $phnums{"kevin"};
    }
[download]

chomp(my $name = <STDIN>);
$name =~ /^$_/ and print ($phnums{$_}.chr 10) for keys %phnums
[download]