Question

Hi I am new to Perl an in a learning process.
I am having an array

 @array = ( 10, 40, 59, 40, 90, 100, 30, 40, 100, 20, );

I want to find the maximum number in the array and also want to know the index where the maximum number is present in my array.

I am doing

my $maxValue = max @array;
print $maxValue;      # displays the maximum number in the entire array

my ($index) = grep $array[$_] eq $maxValue , 0.. $#array;
print ($index);        # this gives me the index of the maximum number which was found in the array. 

The output I am getting is 100 with index 5

But actually 100 is coming 2 times in the array: once at index 6 and again at index 8. My code only provide me the first index it finds with the max value.

How can I get all the index which has maximum value with them?

Answer 1

my @index = grep $array[$_] eq $maxValue , 0.. $#array;
print @index;

Seems to be the simplest way.

Although for numbers, you really should use ==, even though e.g. 100 is also a valid string.