how to check if a number falls in a range?

#!/usr/bin/perl
use strict;
use warnings;

my ($lower, $upper) = (40, 100);

for my $num (17,42,99,111) {

    my $is_between = (sort {$a <=> $b} $lower, $upper, $num)[1] == $nu
+m;
    
    printf "$num is%s between $lower and $upper\n", $is_between ? "" :
+ " not";
}

__END__
17 is not between 40 and 100
42 is between 40 and 100
99 is between 40 and 100
111 is not between 40 and 100
[download]

Or  (not sure which you meant) :

how should I check if the $start and $end in the range of $startPosition and $endPosition?

#!/usr/bin/perl
use strict;
use warnings;
use 5.010;

my ($lower, $upper) = (40, 100);

for my $range ( [10,17],
                [30,71],
                [42,99],
                [83,120],
                [101,111] ) {

    my $is_within = [(sort {$a <=> $b} $lower, $upper, @$range)[1,2]] 
+~~ $range;
    
    printf "[@$range] is%s within [$lower $upper]\n", $is_within ? "" 
+: " not";
}

__END__
[10 17] is not within [40 100]
[30 71] is not within [40 100]
[42 99] is within [40 100]
[83 120] is not within [40 100]
[101 111] is not within [40 100]
[download]

;-)