Not in Perl

In Perl, not is a unary operator that negates its argument. It returns true if the argument is false, and false if the argument is true.

Here are some examples of using the not operator in Perl:

# Using not to negate a boolean value
my $is_weekend = 0;
if (not $is_weekend) {
    print "It's a weekday.\n";
}
# Using not to negate a numerical comparison

my $x = 10;

if (not $x > 20) {

    print "The value of x is less than or equal to 20.\n";

}
# Using not with a regular expression match

my $str = "hello world";

if (not $str =~ /goodbye/) {

    print "The string does not contain the word 'goodbye'.\n";

}

In each of these examples, the not operator is used to negate a condition, either a boolean value, a numerical comparison, or a regular expression match. The if statement evaluates the negation and executes the block of code if the condition is true (i.e., the original condition is false).