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remove entries in perl array with specified value

December 30th, 2014

Assume that in array @array_filtered:

my @array_filtered = ("your", "array", "here", 1, 3, 8, "here", 2, 5, 9, "sit", "here",3, 4, 7,"yes","now",8,1,7,6); #or my @array_filtered=qw(your array here 1 3 8 here 2 5 9 sit here 3 4 7 yes now 8 1 7 6) which uses Alternative Quotes(q, qq, qw, qx)

You want to remove entries that have value "here" or "now" and it's following 3 entries, you can use splice:

#!/usr/bin/perl
my @array_filtered = ("your", "array", "here", 1, 3, 8, "here", 2, 5, 9, "sit", "here",3, 4, 7,"yes","now",8,1,7,6);
my @search_for = ("here","now");
#return keys that have specified value, =~/!~ for regular expression, eq/ne for string, ==/!= for number. or use unless()/if(not()). use m{} instead of // if there's too much / in the expression and you're tired of using \/ to escape them.

$search_for_s=join('|',@search_for);
@index_all = grep { $array_filtered[$_] =~ /$search_for_s/ } 0..$#array_filtered;

for($i=0;$i<=$#index_all;$i++) {
@index_all_one = grep { $array_filtered[$_] =~ /$search_for_s/ } 0..$#array_filtered;
splice(@array_filtered,$index_all_one[0],4);
#print $indexone."\n"
}

print "@array_filtered"."\n";

The output is "your array sit yes 6".

PS:

  • For more info about perl regular expression(such as operators<m, s, tr> and their modifiers, complex regular expression cheat sheet<.\s\S\d\D\w\W[aeiou][^aeiou](foo|bar), \G, $, $&, $`, $'> and more), you can refer to this article.
  • The following is about perl alternative quotes:

q// is generally the same thing as using single quotes - meaning it doesn't interpolate values inside the delimiters.
qq// is the same as double quoting a string. It interpolates.
qw// return a list of white space delimited words. @q = qw/this is a test/ is functionally the same as @q = ('this', 'is', 'a', 'test')
qx// is the same thing as using the backtick operators.

Good Luck!


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