Program to print numbers from 0 to 100 in words

[Jacob Sonia]

Please give me inputs about this program. Like is this a good program, does it follow all conventions. Can this program be done in less number of steps etc.
I am a novice in programming and is doing this so that i can become good in programming.

class Say{
	static String[] print= {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", 

"fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninty", 

"hundred"}; 
	public static void main(String... args){
		try{
			int i = Integer.parseInt(args[0]);
			if(i >= 0 && i < 21)
				System.out.println(print[i]);
			else{
				int length = args[0].length();
				if(length > 3){
					System.out.print("Not an allowed range");
					return;
				}
				char[] arr= args[0].toCharArray();
				int len = length, p = length;
				int Number;
				for(int loop = 0; loop < len || p > 0; loop++){
					Number = Integer.parseInt(Character.toString(arr[loop]));
				if(p == 3 ){
					System.out.print(print[Number]);
					if(Number != 0)
					System.out.print(" hundred");
					p = p - 1;
					continue;
				}
				if(p == 2){
					if(Number != 0){
					switch(Number){
						case 2:
							System.out.print(print[20]);
							break;
						case 3:
							System.out.print(print[21]);
							break;
						case 4:
							System.out.print(print[22]);
							break;
						case 5:
							System.out.print(print[23]);
							break;
						case 6:

							System.out.print(print[24]);
							break;
						case 7:
							System.out.print(print[25]);
							break;
						case 8:
							System.out.print(print[26]);
							break;
						case 9:
							System.out.print(print[27]);
							break;
						}
					}
					  p = p - 1;
					   continue;
					   							
				}
				
				if(p == 1)
					if(Number != 0 && length > 1)
				System.out.print(print[Number]);
					else if(Number == 0 && length == 1){
						System.out.print(print[Number]);
					}
				p = p - 1;
			}
			}
			
		}catch(NumberFormatException e ){
			System.out.println("Please print only digits between 0 to 100");
		}catch(ArrayIndexOutOfBoundsException e){
			System.out.println("Print only numbers in range of 0 to 100");
		}
	}
}    

[Campbell Ritchie]

Lots of people are given that exercise. I would suggest you divide your array into several arrays, putting "eleven" "twelve" . . . "nineteen" in one, and "ten" "twenty" . . . "ninety" in another. Using "" or even "\b" for the 0th element in each may make counting easier.

[Rob Spoor]

You'll also want to use another array for the factors of 10. Forty is not four + ty, and eighty is not eight + ty

[Campbell Ritchie]

Rob Prime wrote:You'll also want to use another array for the factors of 10. Forty is not four + ty, and eighty is not eight + ty

When my daughter taught English in Indonesia she pointed out how many people said "threety" for "thirty". She thought it endearing, but still had to take a mark off for it.

[Jacob Sonia]

Hi,

Thanks for all the inputs. But my first doubt is why are we separating into different arrays. What added advantage would it give. I see that the complexity of an array for getting things at an index is O(1) so how will it make it more efficient.

Thanks for the replies once again.

[pete stein]

Jacob Sonia wrote:
Thanks for all the inputs. But my first doubt is why are we separating into different arrays. What added advantage would it give. I see that the complexity of an array for getting things at an index is O(1) so how will it make it more efficient.

Efficiency is not the crux of this current problem (though this is not to say it never is the main issue), simplicity, correctness, and understandability are the issues here, and using separate arrays to keep like with like will make your program much simpler to implement, to upgrade, and to have others understand.

[fred rosenberger]

Readability is probably the single most important thing to consider when reading code. if I saw this:

case 5: 
   print[23] 
   break;

I would have NO CLUE what that meant. I'd have to refer back to your array each time, and count over to find out what the 23rd element is.

However, this:

case 5:
   tens[5]
   break;

makes more sense - especially after seeing a string array declared as such:

static String[] tens = { "", "teen", "twenty", "Thirty", "Forty"...}