How to remove repeated entries from a Perl array

How to remove repeated entries from a Perl array

Simply assign each elements of array to a key of hash variable.
And extract the keys.

Sample code is as bellow.

#--------------------------------
my @array = qw(3 1 2 3  5 4 2 66 44 55 4 5 6 7 8 9);
print join " ", @array, "\n";
my @array1 = uniq(@array);
print join " ", @array1, "\n";

sub uniq {
    return keys %{{ map { $_ => 1 } @_ }};
}

White LED Light Dangerous

White LED light is more dangerous than orange and yellow ones, says a new study. According to the study, the exposure to white LED bulbs suppresses the production of melatonin in human brain. This can affect our biological clock as against the exposure of orange-yellow LED light bulbs.

An ANI report talking about the study said that Melatonin is responsible for adjusting our biological clock and is known for its anti-oxidant and anti-cancerous properties. Suppressing the production of melatonin causes health-related issues and behaviour disruptions.

The study was conducted by the astronomers, physicists and biologists from ISTIL- Light Pollution Science and Technology Institute in Italy, the National Geophysical Data Centre in Boulder, Colorado, and the University of Haifa. According to the ANI report, researchers had examined the differences in melatonin suppression in a various types of light bulbs, primarily those used for outdoor illumination, such as streetlights, road lighting, mall lighting and the like, for the first time.

The researchers found that the metal halide bulb, which gives off a white light, suppresses melatonin at a rate more than three times greater than the high-pressure sodium HPS bulb that gives off orange-yellow light. Metal Halide bulbs are used as stadium lights. The white LED bulb was found suppressing melatonin at a rate more than five times higher than the HPS bulb.

The report quoted researcher as saying, “The current migration from the now widely used sodium lamps to white lamps will increase melatonin suppression in humans and animals.” The study recently appeared in the Journal of Environmental Management.