Perl4 array scripts

lecture_scripts/change_arrays.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my $favorite_color = 'green';
+my @colors = ('red', $favorite_color, 'cornflower blue', 5);
+
+my $org = join ("--" , @colors );
+
+## push changes the array
+push (@colors , 'black');
+my $new = join ("--" , @colors );
+
+print "org: $org\n";
+print "new: $new\n";
+
+my $last =  pop @colors;
+
+# while tests for truth
+# a list is true if it is not empty ( len > 0 )
+# a list is false when it is empty  ( len == 0)
+while (my $last = pop @colors){
+  print "last is $last\n";
+}
+
+# example of scope and my
+print "$last\n"; ## this will be 'black'

lecture_scripts/favorite_colors.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my $favorite_color = 'green';
+my @colors = ('red', $favorite_color, 'cornflower blue', 5);
+
+$favorite_color = 'black';
+my $second = $colors[1];
+
+print "fc:$favorite_color\tsecond:$second\n";
+
+my $length = scalar @colors;
+#my $length = length @colors; #this is wrong, returns 1
+print "len = $length\n"; 
+

lecture_scripts/join_array.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my $favorite_color = 'green';
+my @colors = ('red', $favorite_color, 'cornflower blue', 5);
+my @colors2 = ('red', $favorite_color, 'cornflower blue', 5);
+
+my $string = join ("\t" , @colors);
+my $string2 = join ("--" , @colors , @colors2);
+
+print $string , "\n";
+print $string2 , "\n";
+## @colors is still the same, not changed by join
+print $colors[0] , "\n";
+

lecture_scripts/loop_control.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @words = qw(I do not like green eggs and ham);
+
+#foreach my $word (sort {uc($a) cmp uc($b)}@words){
+
+foreach my $word (@words){
+  next if $word eq "and";
+  print "$word\n";
+}
+

lecture_scripts/loop_control.pl~

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @words = qw(I do not like green eggs and ham);
+
+#foreach my $word (sort {uc($a) cmp uc($b)}@words){
+
+foreach my $word (@words){
+  next if $word eq "and";
+  print "$word\n";
+}
+

lecture_scripts/map.pl

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+#!/usr/bin/perl
+use strict;
+use warnings;
+
+my @array = qw (a f gf t ffffh j );
+my @map_array = 
+map { my $elem = $_ ; length $elem } @array;
+print "@map_array\n";

lecture_scripts/print_array.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my $favorite_color = 'green';
+my @colors = ('red', $favorite_color, 'cornflower blue', 5);
+
+## no quotes no spaces
+## quotes, array will print with spaces
+print "no quotes: " , @colors , "\n"; 
+print "quotes: @colors\n"; 
+

lecture_scripts/seq_array.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @seqs = qw ( ATGGTGCA TTTTTAA CCCGGG TTTATATATAT );
+
+while (my $seq = shift @seqs){
+ print "seq: $seq\n";
+}  

lecture_scripts/seq_for.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @seqs = qw ( ATGGTGCA TTTTTAA CCCGGG TTTATATATAT );
+
+## length of the array is one more than the last index
+for (my $i = 0 ; $i < scalar @seqs ; $i++){
+ print "seq: $seqs[$i]\n"; 
+}  
+
+print "\n-------\n";
+
+foreach my $seq (@seqs){
+ print "seq: $seq\n";
+}  
+
+print "before while: @seqs\n";
+print "\n-------\n";
+
+##after this while loop, @seqs is empty, len = 0
+while (my $seq = shift @seqs){
+ print "seq: $seq\n";
+}  
+print "after while: @seqs\n";

lecture_scripts/seq_for.pl~

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @seqs = qw ( ATGGTGCA TTTTTAA CCCGGG TTTATATATAT );
+
+## length of the array is one more than the last index
+for (my $i = 0 ; $i < scalar @seqs ; $i++){
+ print "seq: $seqs[$i]\n"; 
+}  
+
+print "\n-------\n";
+
+foreach my $seq (@seqs){
+ print "seq: $seq\n";
+}  
+
+print "before while: @seqs\n";
+print "\n-------\n";
+
+##after this while loop, @seqs is empty, len = 0
+while (my $seq = shift @seqs){
+ print "seq: $seq\n";
+}  
+print "after while: @seqs\n";

lecture_scripts/seq_foreach.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @seqs = qw ( ATGGTGCA TTTTTAA CCCGGG TTTATATATAT );
+
+foreach my $seq (@seqs){
+ print "seq: $seq\n";
+}  
+
+print "before while: @seqs\n";
+print "\n-------\n";
+
+##after this while loop, @seqs is empty, len = 0
+while (my $seq = shift @seqs){
+ print "seq: $seq\n";
+}  
+print "after while: @seqs\n";

lecture_scripts/seq_foreach.pl~

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my @seqs = qw ( ATGGTGCA TTTTTAA CCCGGG TTTATATATAT );
+
+foreach my $seq (@seqs){
+ print "seq: $seq\n";
+}  
+
+print "before while: @seqs\n";
+print "\n-------\n";
+
+##after this while loop, @seqs is empty, len = 0
+while (my $seq = shift @seqs){
+ print "seq: $seq\n";
+}  
+print "after while: @seqs\n";

lecture_scripts/seq_split.pl

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+#!/usr/bin/perl 
+use strict;
+use warnings;
+
+my $seq = "ATGCGACCGGTTAA";
+my @nts = split('',$seq);
+print "seq/array len = " , scalar @nts , "\n";
+print "@nts\n";
+print join("--",@nts),"\n";
+
+my @sorted_nts = sort (@nts);
+print join("--",@sorted_nts),"\n";
+
+

lecture_scripts/sorting.pl

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+#!/usr/bin/perl 
+use warnings;
+use strict;
+
+my $num1 = 10;
+my $num2 = 2;
+my $num3 = 100;
+my $num4 = 5;
+my $num5 = 0;
+
+### bad idea ## my $result_2 = $num1 <=> $num2;
+
+## good idea ##
+my @nums =  ($num1 , $num2 , $num3, $num4 , $num5);
+my @sorted_num = sort {$a <=> $b} @nums;
+
+print "@sorted_num\n";
+
+
+

lecture_scripts/split.pl

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+#!/usr/bin/perl 
+use strict;
+use warnings;
+
+my $string = "I do not like green eggs and ham";
+my @words = split("green",$string);
+print "@words\n";
+print join("--",@words),"\n";
+