PERL

perl post condition

# Basic syntax:
statement if condition;
statement unless condition;

# Example usage:
my $x = 3;
my $y = 5;
# run the statement on the left only if the statement on the right is true
print "x is less than y
" if $x < $y;
--> x is less than y

# run the statement on the left only if the statement on the right is false
print "x is less than y
" unless $x > $y;
--> x is less than y