Significant Digits

[james2010]

I was wondering if php had any way of calculating significant digits.

ie
23.45 + 34 has two significant digits

so the result would be 58 (noting that I rounded up 57.45 - 57.5 - 58)

[Anon]

Why round .45 to 1?

[[deleted]]

manuals manuals manuals... doesn't anybody read them?

http://www.php.net/manual/en/function.round.php

[Anon]

Yeah, but how many digits do you round to? That's what James wanted to know: if PHP can automatically figure out how many significant digits should there be in the result.

James, the answer is no. You'll have to do it yourself if you need to. And I believe Mike is right: 0.45 rounds down to 0. You don't round 0.45 to 0.5 and then to 1.

Diego

[james2010]

Ok thanks, well I'll give it a try. Yeah I realised that after a posted, I rounded .45 to .5 then rounded again after that. I suppose to make a function to find significant digits I would have to count the characters in each string, disregarded trailing zeros or zeros in front of a decimal, ie 123,000,000, or 0.000,000,123