Wednesday 23 October 2019

place and plays $_ in perl?

Method 1:


while(<>)
{
    print;
}

Method 2:


for ('l','s','h','c','g')
{
   print;
   print "\n";
}

Method 3:

@a=split //,'hello';

Method 4:


$_="hello";
$_=~s/he/she/g;

print $_;

Method 5:


$_="he l lo";
for (split)
{
   print;
   print "\n";
}

Method 6:


$_='perlbot';

print if /p/;

Method 7:

foreach ('l','s','h','c','g')
{
   print;
   print "\n";
}

Method 8:


$_ = "prlbot";

print /perl/ ?'perlbot':'normalbot',"\n";

Method 9:


$_="perl";
$_=~tr/p/P/;

print $_;

Method 10:


@a=('l','s','h','c','g');

print grep $_,@a;

Method 11:


@a=('l','s','h','c','g');

print map $_,@a;

Method 12:


%hash=(1,2,7,4,9,6);

while (each %hash) {

 print "$_=$hash{$_}\n";

    }

Method 13:


opendir($_,"/tmp") || die "Can't open dir $!";

@array =readdir($_);

closedir $_;

print @array;

Method 14:

while(<>)
{
    chomp($_);
     print $_;
}

Method 15:


while(<>)
{
    chop($_);
    print $_;
}

Method 16:


while(<>)
{
   chomp($_);
   $output = eval $_;
   print $output;
}

Method 17:


$_="he l lo";

print length($_);

Method 18:


$_="he l k lo";
$v=reverse $_;

print $v;

Method 19:


$_ = 9.0;

print exp $_;

Method 20:


$_ = "10";

print hex $_;

Method 21:


$_ = "Hello Perl Bot";

print index $_, 'Perl';

Method 22:


$_="he l k lo";
$v=lc $_;

print $v;

Method 23:


$_="he l k lo";
$v=uc $_;

print $v;

Method 24:


$_="he l k lo";
$v=ucfirst $_;

print $v;

Method 25:


$_="he l k lo";
$v=lcfirst $_;

print $v;

Method 26:


$_ = "144";

print sqrt $_;

Method 27:


$_ = "Hello Perl Bot Perl";

print rindex $_, 'Perl';

Method 28:


while(($_ = getc) eq 'yes')
{
   print $_;
}

Method 29:


$_ = "Hello Perl Bot Perl";

if (defined $_) {
    print "$_ is defined";
}

Method 30:

$_ = "Hello Perl Bot Perl";

print $_;

Thursday 31 October 2019

Perl In Line Hack - Perform Variable Assigning and Deletion in one Line

Method 1:


($_ = 'hellio') =~ s/i//;

print $_;


Method 2:


s/i// for (my $_ = 'hellio');

print $_;


Method 3:


substr(($_ = 'helloi'), index ($_, "i"), length($_),"")

print $_;


Method 4:


map $_ =~ s/i//,$_='hellio';

print $_;


Method 5:


grep $_ =~ s/i//,$_='hellio';

print $_;


Method 6:


print grep $_=~/[^i]+/,split('',$_='hellio');



Method 7:


map $_=~tr/i//d,$_="hellio";

print $_;


Method 8:


$_=~ s/i// if $_='hellio';

print $_;


Method 9:


$_ =~ tr/i//d if $_ = 'hellio';

print $_;


Method 10:


print grep $_=~/[^i]+/, @_, split '', 'hellio';


Method 11:


print grep $_=~/[^i]+/, "hellio"=~ /./g;


Method 12:


($_='hellio')=~tr/i//d;

print $_;


Method 13:


$_="hellio",$_=~tr/i//d;

print $_;


Method 14:


print @_,grep $_=~/[^i]+/, (split '', 'hellio');


Method 15:


grep $_=~tr/i//d,$_="hellio";

print $_;


kaavannan perl blogspot

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Friday 4 October 2019

how many types available for getting string variable length in perl?

Method 1:

my $c = map $_, $h =~ /(.)/g;


Method 2:

my $c = split '', $h;


Method 3:

my $count = () = "hello" =~ /./g;


Method 4:

print length $h;


Method 5:

$cnt = "hello" =~ tr/[a-z][A-Z][0-9]//;


Method 6:

$h='hello';
my $v=$h=~ s/[a-z]//g;


Method 7:

print  @_ = push(@_, map $_, (split '', 'hellgo'));


Method 8:

print  @_ = push(@_, grep $_, (split '', 'hellgo'));


Method 9:

print push(@_, grep $_, "hello" =~ /./g);


Method 10:

print push(@_, map $_, "hello" =~ /./g);


Method 11:

print push(@_, grep $_, reverse "hello" =~ /./g);


Method 12:

print push(@_, map $_, reverse "hello" =~ /./g);


Method 13:

print push(@_, map $_, (split '', 'hellgo'));


Method 14:


my $c = grep/./, (reverse split '', 'hello');
print $c;


Method 15:

my $c = map $_, (reverse split '', 'hello');
print $c;


Method 16:

my $c = map $_, (reverse "hello" =~ /./g);
print $c;


Method 17:

my $c = grep/./, (reverse "hello" =~ /./g);
print $c;


Method 18:

my $c = map $_, (reverse split '', 'hello');
print $c;


Method 19:

my $c = grep/./, (reverse split '', 'hello');
print $c;


Method 20:

print scalar map $_, 'hello' =~ /(.)/g;


Method 21:

print scalar grep/./,'helloh' =~ /(.)/g;


Method 22:

print scalar  map $_, (reverse "hello" =~ /./g);


Method 23:

print scalar  map $_, (reverse split '', 'hello');


Method 24:

print scalar  map $_, (split '', 'hello');


Method 25:

print $r = @_= map $_, (split '', 'hello');


Method 26:

print $r = @_= grep $_, (split '', 'hello');


Method 27:

print $r = @_= grep $_, (reverse "hello" =~ /./g);


Method 28:

print $r = @_= grep/./,'helloh' =~ /(.)/g


Method 29:

print $r = @_= map  $_, (reverse "hello" =~ /./g);


Method 30:

print $r = @_= map/./,'helloh' =~ /(.)/g


Method 31:

print $r = @_= map $_, (split '', 'hello');


Method 32:

print $r = @_= grep $_, (split '', 'hello');


Method 33:

print $r = @_= grep $_, (reverse "hello" =~ /./g);


Method 34:

print $r = @_= grep/./,'helloh' =~ /(.)/g


Method 35:

print $r = @_= map  $_, (reverse "hello" =~ /./g);


Method 36:

print $r = @_= map/./,'helloh' =~ /(.)/g


Method 37:

print scalar  map $_, (reverse split '', 'hello');


Method 38:

print length reverse  grep/./,'helloh' =~ /(.)/g;


Method 39:

print length reverse  map $_,'helloh' =~ /(.)/g;


Method 40:

print grep/./, (reverse "hello" =~ tr/[a-z][A-Z][0-9]//);


Method 41:

print map $_, (reverse "hello" =~ tr/[a-z][A-Z][0-9]// );




For More Methods Reach Me:@ letscrackperlinterviewblogspot@gmail.com  

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Sunday 24 November 2019

Perl - without reverse function reverse a string

Perl Reverse:
perl reverse function reverses the string which will be very useful for creating or while writing the large code. it saves the time from writing new custom functions for reverse.


Without Perl Reverse Function we can write our custom functions in Perl as below

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Friday 1 November 2019

perl - find missing numbers in array

Method 1:

@a = (1,3,4,6); @c = map $a[$_-1]+1..$a[$_]-1, 1..@a-1; print join(" ", @c);




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Wednesday 11 September 2019

How to print the elements of single hash in Perl without using sort builtin function in many methods?


Method 1:
                           %final=(9,2,1,4,7,6);
                           print "@{[%final]}";

Method  2:
                          %final=(9,2,1,4,7,6);
                          print %final,"\n";

Method  3:
                           %final=(9,2,1,4,7,6);
                           print "$_ $final{$_}\n" for (keys %final);

Method  4:
                           %final=(9,2,1,4,7,6);
                           while (my ($k,$v)=each %final){print "$k $v\n"}

Method  5:
                           %final=(9,2,1,4,7,6);
                           print "$_ => $final{$_}\n" for (sort keys %final);

Method  6:
                     
                          %final=(9,2,1,4,7,6);
                          @d=%final;
                           print @d;

Method  7:
                          %final=(9,2,1,4,7,6);
                          print map { "$_ $final{$_}\n" } keys %final;

Method  8:
                           %final=(9,2,1,4,7,6);
                           print map {$_ . " "} %final, "\n";

Method  9:

                           %final=(9,2,1,4,7,6);
                           foreach(keys %final) { print "$_   $final{$_}\n"; }

Method  10:
                           %final=(9,2,1,4,7,6);
                           map {print "$_  $final{$_}\n"; } keys %final;

Method 11:
                           %final=(9,2,1,4,7,6);
                           print "$_ $final{$_}\n" for keys %final;

kaavannan perl blogspot

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Friday 9 December 2022

how to print the contents of perl hash?

 

Method1

 print "$_ $h{$_}\n" for (keys %h);


Method2:
 
while (my ($k,$v)=each %h){print "$k $v\n"}

Method3:
 
print "@{[%hash]}";

Method4:
 
print map { "$_ $h{$_}\n" } keys %h;

Method5:
 
print "$_ $h{$_}\n" for keys %h

Method6:
 
foreach(keys %my_hash) { print "$_ / $my_hash{$_}\n"; }

Method7:
 
map {print "$_ / $my_hash{$_}\n"; } keys %my_hash;

Method8:
 
print map {$_ . " "} %h, "\n";

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Monday 18 November 2019

Perl Unlink - what is?

Perl Unlink:
perl unlink is used to remove the files. based on our requirements we can delete more than single file using unlink function.
by storing array or list elements  as filename we can achieve group of filenames deletion.


Cons:
1. Unlink will not notify which files could not remove. but it can be manageable using perl warning functions.
2. Unlink will not work on many os.
3. Super user permission necessary for Unlinking a directory although it is not recommended for usual coding.

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