count of digits in large number

[ganache]

here is some code works in c language

Code: Select all

function  countDigit(n As Ulongint) As Integer
return INT(log(10(n)) + 1)
end function 
 
Dim As Integer n 
input "Enter number: ";n
print countDigit(n)
Sleep

But compiler says expected '' ( " in return statement. No matter how i try to balance the brackets, it still complains.

[SARG]

Hi

Change log(10(n)) by log (n)

Edit : note natural logarithm, divide by log(10) if the need is logarithm of base 10

Code: Select all

function  countDigit(n As Ulongint) As Integer
return INT((log(n)/log(10)) + 1)
end function
 
Dim As Integer n
input "Enter number: ";n
print countDigit(n)
sleep

[fxm]

But since the Log-based 10 built-in function does not exist in FreeBASIC, the division of Log(n) by Log(10) introduces a rounding error, and therefore the final function may have an error on the number of digit at the borders ( 9-10, 99-100, 999-1000, ...).

[Provoni]

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print len(str(n))

[dodicat]

The crt gives a log10

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#include "crt.bi"
function  countDigit(n As Ulongint) As Integer
return INT(log10(n) + 1)
end function
 
Dim As Integer n
input "Enter number: ";n
print countDigit(n)
Sleep 

[ganache]

thanks guys for the suggestions.
But it seems that the log method is incorrect. Tried it in c.
The code below works for numbers that fit into the largest numeric data type supported
by FB. After that I guess the integers start to overflow...

Code: Select all

Dim As Ulongint number
Dim As Integer count
input "Enter a integer number: ",number
while number > 0
number /= 10
count +=1
wend
print "No. of digits is: ";count
Sleep
End