Learning Perl Chapter 1 exercise

Posted on Netease blog 13:10:11

1st print the last name based on the entered person name

#! Perl-W
# Getfamilyname
Use strict;
My % nametable = ("Fred" => "Flintstone", "Barney" => "rubble", "Wilma" => "Flintstone ");
Print "input person name, and the program will print his familyname. \ n ";
My $ personname = <stdin>;
Chomp ($ personname );
If (exists $ nametable {$ personname }){
Print "Peron $ {personname}'s familyname is $ nametable {$ personname} \ n ";
} Else {
Print "No such person \ n ";
}
2nd print the number of words entered

#! Perl-W
Use strict;
My % wordcounter;
My $ word;
# While (Chomp ($ word = <stdin>) will report an error saying that an uninitialized $ word value is used.
While ($ word = <stdin> ){
Chomp ($ word );
If (exists $ wordcounter {$ word }){
$ Wordcounter {$ word} + = 1;
} Else {
$ Wordcounter {$ word} = 1;
}
}
My $ key;
My $ value;
Print "Print wordcounter without order. \ n ";
While ($ key, $ value) = each % wordcounter ){
Print "$ key, \ t $ value \ n ";
}
Print "Print wordcounter with ASCII order \ n ";
My @ orderdkeys = sort keys % wordcounter;
Foreach (@ orderdkeys ){
Print "$ _, \ t $ wordcounter {$ _} \ n ";
}

3rd question print system environment variables

#! Perl-W
Use strict;
Print "print system env with ASCII orders \ n ";
My @ keys = sort (Keys % env );
My $ key_len = 0;
Foreach (@ keys ){
If (length ($ _)> $ key_len ){
# Length is a regular function, so you do not need to use the & length ($ _) method when calling it.
$ Key_len = length ($ _);
}
}
My $ format = "%-$ {key_len} s \ t % s \ n ";
Foreach (@ keys ){
Printf $ format, "$ _", "$ ENV {$ _}";
}