CY's Take on PWC#110
If you want to challenge yourself on programming, especially on Perl and/or Raku, go to https://perlweeklychallenge.org, code the latest challenges, submit codes on-time (by GitHub or email).
Do tell me, if I am wrong or you strongly oppose my statements!
Well, I wake up early and get some time to blog about The Weekly Challenge again (in addition, correct some parts of my submitted code ‐ a brain with good rest well spots bugs!).
Both Perl and (guest language) Java codes for the two tasks have been done this week.
Task 1: Valid Phone Number
I started my Sunday afternoon with Java. "Eat the frog first."
There are several ways to read text files in Java, I chose the default class which I am most familiar with: java.util.Scanner.
File file = new File(args[0]);
Scanner sc = new Scanner(file);
while (sc.hasNextLine()) {
// blah blah blah
}
Before I started, I peeked on the Guest Contribution
page and briefly looked what packages the regular Java contributor Mr
Zia use, and intentionally avoided repetition. Oh, Mr Zia used Java
Regex in Task 1 and some usual packages for Task 2. Though not every
programming language works with the TIMTOWTDI motto, for Task 1 we can
have different approaches.
Actually I am not familiar Java Regex yet. I divided the verification process into three parts:
- Check the first 4 characters;
- check the character in between regional calling codes and the latter codes is an empty space character;
- finally check the last 10 characters are digits.
Perl codes:
my $s;
while ($s = <STDIN>) {
chomp($s);
if ( length $s == 15 &&
substr($s, 4, 1) eq " " &&
substr($s, -11) =~ / \d{10}/ &&
(substr($s,0,4) =~ /\d{4}/ ||
substr($s,0,4) =~ /\+\d{2}/ ||
substr($s,0,4) =~ /\(\d{2}\)/)
) {
print $s, "\n";
}
}
Selection of Java codes:
while ($s = <STDIN>) {
chomp($s);
if ( length $s == 15 &&
substr($s, 4, 1) eq " " &&
substr($s, -11) =~ / \d{10}/ &&
(substr($s,0,4) =~ /\d{4}/ ||
substr($s,0,4) =~ /\+\d{2}/ ||
substr($s,0,4) =~ /\(\d{2}\)/)
) {
print $s, "\n";
}
}
if ( checkHead(num) && checkMid(num) &&
num.substring(5).trim().length() == 10 && checkTail(num))
System.out.println(num);
// blah blah blah
private static boolean isNumeric(char ch)
{
if (ch >= '0' && ch <= '9') return true;
else return false;
}
It is also worth mentioned that Java requires attention for exception
handling whenever the file I/O package is being used. From my limited
exploration, the exception handling feature is closely linked with
object-oriented programming. Exception handling in Perl requires a Perl
hacker with expertise to discuss.
Task 2: Transpose File
After reading the task statement on Monday, immediately I thought
of the Perl module for CSV file, hence I thought it would be a sincere
task in Perl. From the search engine, it is recommended that the use of
already-made external packages for CSV file in Java; but I thought it is
okay to handle the special cases (for example, the delimitter comma is
used in a field) by myself.
Some CSV files were made from LibreOffice for testing:
task2_str2.csv """",",",char ok,pdl,int cu,uml,str
task2_str4.csv """",okay,char ok,pdl,int cu,uml,str
task2_ex2.csv (when the number of fields in each row is not the same) name,age,sex Mohammad,45,m,n Joe,20,m Julie,35,f Cristina,10,f
Expected Output name,Mohammad,Joe,Julie,Cristina age,45,20,35,10 sex,m,m,f,f ,n,,,
For Java, I made use of ArrayList<ArrayList<String>>. Omitting the details here.
For Perl, Text::CSV_XS did a good job. But I want quotation marks protecting the comma and handling cases like task2_ex2.csv, therefore a subroutine for printing is added:
sub print_item {
my $item = $_[0];
if (defined($item)) {
print "\"" if $item =~ /,/;
print $item;
print "\"" if $item =~ /,/;
}
}
my $item = $_[0];
if (defined($item)) {
print "\"" if $item =~ /,/;
print $item;
print "\"" if $item =~ /,/;
}
}
Perl Script Output:
# the example from task statement name,Mohammad,Joe,Julie,Cristina age,45,20,35,10 sex,m,m,f,f # task2_str2.csv ",ok,cu ",",pdl,uml char,int,str # task2_str4.csv ",ok,cu okay,pdl,uml char,int,str # task2_ex2.csv name,Mohammad,Joe,Julie,Cristina age,45,20,35,10 sex,m,m,f,f ,n,,,
Differences from my Java compiled program for task2_str2.csv , task2_str4.csv:
# task2_str2.csv """",ok,cu
",",pdl,uml
char,int,str
# task2_str4.csv """",ok,cu okay,pdl,uml char,int,str
Oooops... it seems that the """" for the output is better. See RFC 4180 Section 2, point 7. ...
Stay alert and healthy! □
This blog is inactive and replaced by https://e7-87-83.github.io/coding/blog.html ; but I post highly Perl-related posts here.
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