Added comments to Java classes showing how to run the programs.

3 files changed, 44 insertions, 23 deletions

diff --git a/java/02-hello/Hello.java b/java/02-hello/Hello.java
index bacee99..764f59f 100644
--- a/java/02-hello/Hello.java
+++ b/java/02-hello/Hello.java
@@ -1,3 +1,7 @@
+/*
+* Run this as below:
+*   java Hello Kamal
+*/
 public class Hello {
     public static void main(String[] args) {
         System.out.println("Hello " + args[0]);
diff --git a/java/03-count/Count.java b/java/03-count/Count.java
index cbc651e..4d1abd5 100644
--- a/java/03-count/Count.java
+++ b/java/03-count/Count.java
@@ -1,29 +1,39 @@
+/*
+ * Run this as below:
+ *    java Count
+ *    java Count 1
+ *    java Count 3 8
+ *    java Count 5 1
+ *    java Count 2 Kamal
+ *    java Count 5 12.3
+ *    java Count 3 10000000000000000000000000000000000000000000000000
+ */
 public class Count {
-    public static void main(String[] args) {
-	if (args.length < 2) {
-	    System.err.println("[ERROR] Type two integers as arguments.");
-	    System.exit(1);
-	}
+  public static void main(String[] args) {
+    if (args.length < 2) {
+      System.err.println("[ERROR] Type two integers as arguments.");
+      System.exit(1);
+    }
+
+    int start = 0;
+    int end = 0;
 
-	int start = 0;
-	int end = 0;
-	
-	try {
-	    start = Integer.parseInt(args[0]);
-	    end = Integer.parseInt(args[1]);
-	} catch(NumberFormatException nfe) {
-            System.err.println("[ERROR] You didn't provide integer arguments.");
-	    //System.err.println("Details: " + nfe.getMessage());
-	    System.exit(2);
-	}
+    try {
+      start = Integer.parseInt(args[0]);
+      end = Integer.parseInt(args[1]);
+    } catch (NumberFormatException nfe) {
+      System.err.println("[ERROR] You didn't provide integer arguments.");
+      // System.err.println("Details: " + nfe.getMessage());
+      System.exit(2);
+    }
 
-	if(start > end) {
-	    System.err.println("[ERROR] Start is greater than end.");
-	    System.exit(3);
-	}
+    if (start > end) {
+      System.err.println("[ERROR] Start is greater than end.");
+      System.exit(3);
+    }
 
-        for(int i = start; i <= end; i++) {
-            System.out.println(i);
-	}
+    for (int i = start; i <= end; i++) {
+      System.out.println(i);
     }
+  }
 }
diff --git a/java/04-factorial/Factorial.java b/java/04-factorial/Factorial.java
index 0b2e650..f81c54a 100644
--- a/java/04-factorial/Factorial.java
+++ b/java/04-factorial/Factorial.java
@@ -1,3 +1,7 @@
+/*
+* Run this as:
+*    java Factorial
+*/
 public class Factorial {
     public static void main(String[] args) {
         int x = factorial(5);
@@ -11,6 +15,9 @@ public class Factorial {
         System.out.println(factorial(3));
     }
 
+    /*
+    * Here is a subroutine defined. In Java, we call it a method.
+    */
     public static int factorial(int x) {
         if (x == 0) {
             return 1;