All posts by WhiteWind

About WhiteWind

I'm a Perl-PHP Developer from India. I'm a great fan of Wordpress & Perl.

Change content order using regular expression in perl

Perl Scripts

It can be done as follows :-

my $date = "2009-27-02";
$date =~ s/(\d{4})-(\d{2})-(\d{2})/$2\/$3\/$1/;
say $date;

O/p

27/02/2009

How to order contents using specific values in a field using MySql?

MySQL Queries, Uncategorized

It can be done as follows:-

SELECT * FROM table_name ORDER BY FIELD(filed_name,"value_y","value_x") DESC

innerHTML not working in Internet Explorer(IE)

Java Scripts, Uncategorized

We may see that we don’t get proper output in IE when we try to use

document.getElementById('my_id').innerHTML="mm";

This mainly happens in the case we try to implement innerHTML into the select tag. The way I recommend to overcome this situation is to use jquery. We can write the content in jquery as follows:

$('#my_id').html("<option value='mm'>mm</option>");

I had tested it and saw that it’s working.

Multidimesional array in perl…

Perl Scripts, Uncategorized

We can write multidimensional array in Perl as follows :

    my @array1 = (1, 2, 3, 'four');
    my $reference1 = \@array1;
    my @array2 = ('one', 'two', 'three', 4);
    my $reference2 = \@array2;

    my @array = (\@array1, \@array2);

    print $array[1]->[0];

The output will be as follows :

one

How to generate random number in perl using rand()?

Perl Scripts, Uncategorized

Using the Perl rand() function

Introduction

The rand() function is used to generate random numbers. By default it generates a number between 0 and 1, however you can pass it a maximum and it will generate numbers between 0 and that number.

Example 1. Between 0 and 1

To generate a random decimal number between 0 and 1, use rand() without any parameters.

  #!/usr/bin/perl
  use strict;
  use warnings;

  my $random_number = rand();

  print $random_number . "\n";

This will give you a random number, like:

  0.521563085335405

Example 2. A bigger range of numbers

Quite often you don’t want a number between 0 and 1, but you want a bigger range of numbers. If you pass rand() a maximum, it will return a decimal number between 0 and that number. Our example below generates a random number between 0 and 100.

  #!/usr/bin/perl
  use strict;
  use warnings;

  my $range = 100;

  my $random_number = rand($range);

  print $random_number . "\n";

The program will produce something like:

  34.0500569277541

Example 3. A random integer

To generate a random integer, convert the output from rand to an integer, as follows:

  #!/usr/bin/perl
  use strict;
  use warnings;

  my $range = 100;

  my $random_number = int(rand($range));

  print $random_number . "\n";

This program gives you an integer from 0 to 99 inclusive:

  68

Example 4. With an offset

To generate a random number between, for example, 100 and 150, simply work out the range and add the minimum value to your random number.

  #!/usr/bin/perl
  use strict;
  use warnings;

  my $range = 50;
  my $minimum = 100;

  my $random_number = int(rand($range)) + $minimum;

  print $random_number . "\n";

This program gives you:

  129