Re: filtering an array

[jwkrahn]

in reply to filtering an array

push @positions, [ $read->end + 1, $base ];

i would like to remove every line of this array that contains a G or a T as the string

@positions = grep $_->[ 1 ] =~ /ac/i, @positions;

i would like to get rid of the strings altogether, so i just have an array with one column representing the number

@positions = map $_->[ 0 ], @positions;

[prbndr]

this code gives the warning: Use of uninitialized value in pattern match (m//). what exactly does this mean?

[philiprbrenan]

You are using a variable in a pattern matching regular expression and said variable currently has no value. Please try assigning a value to the variable and see what happens. Thanks.

[prbndr]

i see. so if my array @positions is already defined and created, do i need to loop over all the values in @positions and then execute the code you posted?

something like:

 for (@positions) {@positions = grep $_->[1] =~ /ac/i, @positions;}

and then:

 for (@positions) {@positions = map $_->[0], @positions;}