Perl: Searching for item in an Array

Question

Given an array @A we want to check if the element $B is in it. One way is to say this:

Foreach $element (@A){
    if($element eq $B){
        print "$B is in array A";
    }
}

However when it gets to Perl, I am thinking always about the most elegant way. And this is what I am thinking: Is there a way to find out if array A contains B if we convert A to a variable string and use

index(@A,$B)=>0

Is that possible?

Answer 1

There are many ways to find out whether the element is present in the array or not:

1. Using foreach

   foreach my $element (@a) {
       if($element eq $b) {
          # do something             
          last;
       }
   }
   

2. Using Grep:

   my $found = grep { $_ eq $b } @a;
   

3. Using List::Util module

   use List::Util qw(first); 
   
   my $found = first { $_ eq $b } @a;
   

4. Using Hash initialised by a Slice

   my %check;
   @check{@a} = ();
   
   my $found = exists $check{$b};
   

5. Using Hash initialised by map

   my %check = map { $_ => 1 } @a;
   
   my $found = $check{$b};