Please assist convert numbers from 0 to 999999999999999, to words.my program does not exceed ten numbers.

Quote:

Create a function that takes a numeral (just digits without separators (e.g. 19093 instead of 19,093) and returns the standard way of reading a number, complete with punctuation.

Examples
sayNumber(0) ➞ "Zero."

sayNumber(11) ➞ "Eleven."

sayNumber(1043283) ➞ "One million, forty three thousand, two hundred and eighty three."

sayNumber(90376000010012) ➞ "Ninety trillion, three hundred and seventy six billion, ten thousand and twelve."
Notes
Must read any number from 0 to 999,999,999,999,999.

class SayTheNumber {
    // These are our numbers from which we will extract our words.
    private static String[] less_than_twenty = {"","One","Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten","Eleven","Twelve","Thirteen","Fourteen","Fifteen","Sixteen","Seventeen","Eighteen","Nineteen"};
    
    private static String[] tens = {"","","Twenty","Thirty","Forty","Fifty","Sixty","Seventy","Eighty","Ninety"};
    
    private static String[] chunks = {"","Thousand","Million","Billion","Trillion"};
    
    // This function takes the numerical value and breaks it into parts with 3 digit each.
    // Then it passes it to next function coupled with it that will build the string for it.
    public static String sayNumber(long num) {
       if(num==0) return "Zero.";
        
        String ans = new String();
        
        int index=0;
        while(num>0){
            if(num%1000!=0){
                ans = convertThreeDigit(num%1000) + chunks[index]+", " + ans;
            }
            index++;
            num/=1000;
        }
        // for perfecting our punctuation, we will use substring and trim methods.
        return ans.trim().substring(0,ans.length()-3)+".";
        
    }

    // This function recieves the 3 digit number and builds the string.
    // Its a recursive function.
    private static String convertThreeDigit(long num){
        if(num==0)return "";
        if(num<20) return less_than_twenty[(int)num]+" ";
        
        else if(num<100) return tens[(int)num/10] + " " + convertThreeDigit(num%10);
        
        else return less_than_twenty[(int)num/100] + " "+"Hundred"+" "+convertThreeDigit(num%100);
    }

    // Finally our driver class to test our inputs.
    public static void main(String[] args) {
        long n1 = 0;
        long n2 = 11;
        int n3 = 1254367125;
        System.out.println(sayNumber(n1)+"\n"+sayNumber(n2)+"\n"+sayNumber(n3));
    }
}