perl - array and hash common differences

S.No	ARRAYS	HASHES
1.          2.          3.                      4.                            5.                     6.            7.                      8.                    9.       10.       11.      12.       13.        14.        15.	It is ordered data collection Data Can be accessed based on index value Stack operations performed using push,pop,shift,unshift Duplicate Elements will be exist in Array For Large data, Arrays will not be in speed as getting values from hash keys. Arrays can be created using () brackets @array=(1,3,5,6,2); For More methods refer this link. https://kaavannan-perl.blogspot.com/2019/11/perl-array-what-is.html for accessing array index $array[1]; Array can be accessed in loops as below 1.For(@array) { } 2.foreach(@array1,@array2)    {        Print $_;    } 3.print grep{},@array; 4. print map{},@array; Array slices can be used as below @array[2]; To find length of an array  $#array+1;        or scalar(@array);       or $a=@array; For Emptying Array $#array = -1;      or @array = ( ); To reverse an array print reverse @array; To sort array Elements ascending order @a=sort{$a <=> $b }@array; desending order @a=sort{$b <=> $a }@array; To add array elements $array[0]='55'; To Delete array elements delete $array[1];	It is unordered Data Collection Data Can be accessed based on Key value Stack operations cannot be performed Keys will not have Duplicate elements but Values would have Duplicate elements. Based on hash Keys Data retrival would be fast Hash is also possible to create using () bracket %hash=(1,3,5,6,2); For More methods refer this link. https://kaavannan-perl.blogspot.com/2019/10/perl-hashes-what-is.html For accessing hash index use the key name $hash{1}; Hash can be accessed based on keys and values While(($k,$vals) = each %h) {     Print “$k,$vals\n”; } Foreach $k (keys %h) { Print “$k => $hash{$k}\n”; } Foreach $values (values %hash) { Print “$values\n”; } Hash slices can be used as below, $hash{'1'} To find length of hash @array=keys %hash; scalar(@array);      or $#array+1;      or $a=@array; For Emptying hash %hash=( ); To reverse a hash print reverse %hash; To sort hash elements  foreach $k (sort keys %hash) {    print "$k => $hash{$k}\n"; } To add hash Elements $hash{1}='one'; To Delete hash elements delete($hash{'1'});

Perl Data Structures - Arrays of Arrays

Creating Arrays of Arrays:

Method 1:

 @array=(["apple","orange"],["Mango","Banana"],["Papaya","Peach"]);

 print $array[0][1];

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How Many Possible ways to remove Duplicates in an array using perl?

Method 1:

sub filter {
    my %hash;
    grep !$hash{$_}++, @_;
}

my @array = qw(e f g h i);
my @final= filter(@array);


Method 2:

use List::MoreUtils qw(uniq);
my @array = qw(1 1 1 2 3 4 4);
my @final= uniq(@array);


Method 3:

my %hash = ();
foreach my $item (@array)
{
    $hash{$item}++;
}
my @final = keys %hash;


Method 4:

my @array=qw( 3 2 3 4 4 3 2);
my @final=keys %{{ map{$_=>1}@array}};
print join ' ', sort{$a<=>$b} @final;


Method 5:

%hash=();
my @array = qw(e j g h i);
@final = grep { ! $hash{$_} ++ } @array;


Method 6:

my @array;
my @finals;

foreach my $var ( @array )
{
    if (! grep(/$var/, @finals ))
    {
          push( @finals, $var );
     }
}


Method 7:

my @array = qw(e f g h i);
my %hash;
@hash{@array}=(1..@array);
@final=keys%hash;


Method 8:

my @final = keys {map {$_ => 1} @array};


Method 9:

@array = qw(e f g h i);
%hash1   = map { $_ => 1 } @array;
@final = keys %hash1;


Method 10:
my @array = qw(e f g h i);
my %hash;
foreach my $v (@array){
        $hash{$v}=1;
}
@final=keys%hash;


kaavannan perl blogspot

perl data structures tutorial - part1

Perl provides a rich set of data structures that can be used to store and manipulate data. In this tutorial, I'll cover the most commonly used data structures in Perl, along with code examples.

Arrays

Arrays are ordered lists of scalar values. To declare an array, you use the @ symbol followed by the array name. Here's an example:

@my_array = (1, 2, 3, 4, 5);

You can access individual elements of the array using the array name followed by the index of the element in square brackets. Here's an example:

print $my_array[0];  # prints 1

You can also use the scalar function to get the number of elements in an array:

print scalar(@my_array);  # prints 5

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print final element of an array reference using perl?

.Method 1:

                       @array=(1,33,11,4,5);
                       $r=\@array;
                        print  "@$arr_ref [-1]";

Method 2:

                       @array=(1,33,11,4,5);
                       $r=\@array;
                        print  $arr_ref->[-1];

Method 3:

                       @array=(1,33,11,4,5);
                       $r=\@array;
                        print @$r[$t-1]=$t=scalar(@$r);

Method  4:

                       @array=(1,33,11,4,5);
                       $r=\@array;
                        print splice(@$r,scalar(@$r-1),1);


 Method  5:

                        @array=(1,33,11,4,5);
                        $r=\@array;
                        print @$r[($#=@$r-1)];

 Method  6:

                        @array=(1,33,11,4,5);
                        $r=\@array;
                        print @$r[scalar(@$r-1)];

Method 7:
                       @array=(1,33,11,4,5);
                        $r=\@array;
                        print splice(@$r,-1,scalar(@$r-1));




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

Component Iteration in React JSX Strategies for Seamless Repetition

 Transitioning from traditional templating to JSX in React can be a bit perplexing, especially when you’re accustomed to looping constructs like for. In JSX, which ultimately compiles down to JavaScript function calls, you need to employ a different approach to achieve repetitive rendering. Let’s explore various techniques to repeat components in JSX.

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perl array - what is?

Perl Arrays:

Array is a collection of ordered elements, which is assigned by more than one elements like scalars,strings,numbers,floating points etc.

Creating Arrays:

Method 1:

@array=(8,1,3,-6,2);

print @array;

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write 1000 uniq perl interview questions and answers to master in perl part 2

 251. Q: In Perl, how can you find the position of a substring within a string?

1A: In Perl, you can find the position of a substring within a string by using the `index` function. Here is an example:
2
3```perl
4use strict;
5use warnings;
6
7my $string = 'Hello, World! World is beautiful.';
8my $substring = 'World';
9
10my $position = index $string, $substring;
11
12if ($position == -1) {
13    print "The substring was not found in the string.\n";
14} else {
15    print "The substring was found at position: $position\n";
16}
17```
18
19In this example, the script finds the position of the substring `'World'` within the string `'Hello, World! World is beautiful.'` and prints the resulting position.

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