| Re: counting the digits in a number, exponential format problem [message #171032 is a reply to message #171031] |
Wed, 15 December 2010 16:15  |
Jerry Stuckle
Messages: 2598
Registered: September 2010
Karma:
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Senior Member |
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On 12/15/2010 10:53 AM, -matt wrote:
> @Alvaro: thanks for your reply. i am by no means a PHP expert
> (obviously) so this is all good information.
>
>> Alright, you don't really want to know the length of a numeric variable.
>> You know to want the length of its string representation. That's easy to
>> calculate but clearly depends of how you want to display the number:
>
> exactly!!! the only problem is that i have no control of how the
> number comes to me, nor how it is displayed later. however, it is
> always displayed using full decimal form with the least number of
> digits and no commas. for example: 1234 not 1,234.0, etc. the problem
> i was having is how PHP changes its conversion process to strings for
> float from E-4 to E-5. that is what has been really throwing me off.
> however, i think i have a working solution now for my original
> problem. below is my function if anyone cares to see my solution:
>
> function numberOfDigits($value)
> {
> if(!is_numeric($value))
> {
> return 0;
> }
> if((int)$value == $value)
> {
> return strlen((int)$value);
> }
> for($i=1; $i<=10; $i+=1)
> {
> $temp = $value * pow(10,$i);
> if((int)$temp == $temp)
> {
> if((int)$value == 0)
> {
> return $i + 1;
> }
> else
> {
> return strlen($temp);
> }
> }
> }
> return strlen((int)$value) + 10;
> }
>
> echo numberOfDigits(1); // '1'
> echo numberOfDigits(123.456); // '6'
> echo numberOfDigits(1.0); // '1'
> echo numberOfDigits(0.33); // '3'
> echo numberOfDigits(0.033); // '4'
> echo numberOfDigits(0.0033); // '5'
> echo numberOfDigits(0.00033); // '6'
> echo numberOfDigits(3.3E-5); // '7'
> echo numberOfDigits(3.3E-6); // '8'
> echo numberOfDigits(3.3E-7); // '9'
>
> i use a for loop which only goes to $i=10 because i really only care
> about numbers down to E-9ish. clearly you could change that to a while
> loop or something and make the function more general.
>
> thanks again everyone for all the help and information.
But you DO have control. Just format the number yourself, instead of
using the default PHP formatting.
The defaults are there to make life easier. However, they don't work in
all circumstances. When that happens, there are (almost, anyway) always
ways to do the job yourself.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
==================
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