GateKiller - 1 year ago 78
C# Question

# Convert integers to written numbers

Is there an efficient method of converting an integer into the written numbers, for example:

``````string Written = IntegerToWritten(21);
``````

would return "Twenty One".

Is there any way of doing this that doesn't involve a massive look-up table?

This should work reasonably well:

``````public static class HumanFriendlyInteger
{
static string[] ones = new string[] { "", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine" };
static string[] teens = new string[] { "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen" };
static string[] tens = new string[] { "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety" };
static string[] thousandsGroups = { "", " Thousand", " Million", " Billion" };

private static string FriendlyInteger(int n, string leftDigits, int thousands)
{
if (n == 0)
{
return leftDigits;
}

string friendlyInt = leftDigits;

if (friendlyInt.Length > 0)
{
friendlyInt += " ";
}

if (n < 10)
{
friendlyInt += ones[n];
}
else if (n < 20)
{
friendlyInt += teens[n - 10];
}
else if (n < 100)
{
friendlyInt += FriendlyInteger(n % 10, tens[n / 10 - 2], 0);
}
else if (n < 1000)
{
friendlyInt += FriendlyInteger(n % 100, (ones[n / 100] + " Hundred"), 0);
}
else
{
friendlyInt += FriendlyInteger(n % 1000, FriendlyInteger(n / 1000, "", thousands+1), 0);
if (n % 1000 == 0)
{
return friendlyInt;
}
}

return friendlyInt + thousandsGroups[thousands];
}

public static string IntegerToWritten(int n)
{
if (n == 0)
{
return "Zero";
}
else if (n < 0)
{
return "Negative " + IntegerToWritten(-n);
}

return FriendlyInteger(n, "", 0);
}
}
``````

(Edited to fix a bug w/ million, billion, etc.)

Recommended from our users: Dynamic Network Monitoring from WhatsUp Gold from IPSwitch. Free Download