Add all the A tasks

Task/Associative-array-Iteration/Perl/associative-array-iteration.pl

@@ -0,0 +1,32 @@
+#! /usr/bin/perl
+use strict;
+
+my %pairs = ( "hello" => 13,
+	      "world" => 31,
+	      "!" => 71 );
+
+# iterate over pairs
+
+# Be careful when using each(), however, because it uses a global iterator
+# associated with the hash. If you call keys() or values() on the hash in the
+# middle of the loop, the each() iterator will be reset to the beginning. If
+# you call each() on the hash somewhere in the middle of the loop, it will
+# skip over elements for the "outer" each(). Only use each() if you are sure
+# that the code inside the loop will not call keys(), values(), or each().
+while ( my ($k, $v) = each %pairs) {
+    print "(k,v) = ($k, $v)\n";
+}
+
+# iterate over keys
+foreach my $key ( keys %pairs ) {
+    print "key = $key, value = $pairs{$key}\n";
+}
+# or (see note about each() above)
+while ( my $key = each %pairs) {
+    print "key = $key, value = $pairs{$key}\n";
+}
+
+# iterate over values
+foreach my $val ( values %pairs ) {
+    print "value = $val\n";
+}