Examples for Chapter 3 written in Perl 5 (#71)

* Create 01_countdown.pl

Recursion example #1 written in Perl 5

* Create 02_greet.pl

Recirsion example #2 written in Perl 5

* Create 03_factorial.pl

Recursion example #3 written in Perl 5

03_recursion/perl5/01_countdown.pl

@@ -0,0 +1,15 @@
+sub countdown {
+
+    my $i = shift;
+
+    print "$i\n";
+
+    # base case:
+    return if $i <= 1;
+
+    # recursive case
+    countdown( $i - 1 );
+
+}
+
+countdown(5);

03_recursion/perl5/02_greet.pl

@@ -0,0 +1,23 @@
+sub greet2 {
+
+    my $name = shift;
+
+    print "how are you, $name ?\n";
+}
+
+sub bye { print "ok bye !\n"; }
+
+sub greet {
+
+    my $name = shift;
+
+    print "hello, $name !\n";
+
+    greet2($name);
+
+    print "getting ready to say bye...\n";
+
+    bye();
+}
+
+greet('adit');

03_recursion/perl5/03_factorial.pl

@@ -0,0 +1,13 @@
+sub fact {
+
+    my $x = shift;
+
+    if ( $x == 1 ) {
+        return 1;
+    }
+    else {
+        return $x * fact( $x - 1 );
+    }
+}
+
+print fact(5), "\n";