Perl intelligent match

1. perl ~~ For intelligent matching, it can intelligently Determine operations based on the operands on both sides of the symbol.

To determine whether an element exists in an array, do not use smart matching. The program is like this:

my $x=2;my @array=(1,2,3);my $flag=0;for (@array){if($x==$_){$flag=1;}}if($flag == 1){print "$x is in the array";}else{print "$x is not in the array";}

Use smart matching, the program is like this:

my $x=2;my @array;if(@array~~$x){print "$x is in the array";}else{print "$x is in the array";}

Check whether a key value exists in the hash table.

'Hello '~~ {Hello => 1, world => 2} returns true

2. The priority of intelligent matching is in the online perl document. Intelligent Matching selects matching based on the order of the table, and the priority gradually decreases from top to bottom.

     $a      $b        Type of Match Implied    Matching Cod    ======  =====     =====================    =============    Hash    Hash      hash keys identical      [sort keys %$a]~~[sort keys %$b]    Hash    Array     hash slice existence     grep {exists $a->{$_}} @$b    Hash    Regex     hash key grep            grep /$b/, keys %$a    Hash    Any       hash entry existence     exists $a->{$b}    Array   Array     arrays are identical[*]    Array   Regex     array grep               grep /$b/, @$a    Array   Num       array contains number    grep $_ == $b, @$a    Array   Any       array contains string    grep $_ eq $b, @$a    Any     undef     undefined                !defined $a    Any     Regex     pattern match            $a =~ /$b/    Code()  Code()    results are equal        $a->() eq $b->()    Any     Code()    simple closure truth     $b->() # ignoring $a    Num     numish[!] numeric equality         $a == $b    Any     Str       string equality          $a eq $b    Any     Num       numeric equality         $a == $b    Any     Any       string equality          $a eq $b