What this syntax really is ?

for my $i (0 .. $#array) {
    for my $j (0 .. $#array) {
        next if $j == $i;
        # Compare $i, $j
    }
}
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and

for my $i (0 .. $#array - 1) {
    for my $j ($i + 1 .. $#array) {
        # Compare $i, $j

    }
}
[download]

is it c++ , i mean i can't understand the statements ..