How to do decimal number validation in PHP?
:)
(The decimal point is optional) it should accept ... 0 , 1 , 2 , 0.123 , 0.2 , 12.34 etc.
xcellent ... thanx a lot... such a fn. was available? i was googling like anything... !
dev646
2010-02-09 10:14:32
@dev646: Make sure you read the comments on the is_float function page. They are really helpful
AntonioCS
2010-02-09 10:34:29
A:
if (is_integer($num) || is_float($num)) {
// OK :)
} else {
// Not so good... :/
}
TiuTalk
2010-02-09 09:51:39
@Tatu Ulmanen - Use the correct data type when you want to trust in your validation
TiuTalk
2010-02-09 10:00:24
@TiuTalk, but take in account that you cannot affect the data type when you get your variables through a $_POST request, for example.
Tatu Ulmanen
2010-02-09 10:02:14
@Tatu Ulmanen - But you cant' just rely on the $_POST or $_GET data.. You need some modifications, sanitizations and THEN validations. That's what I think
TiuTalk
2010-02-09 10:05:10
A:
suggested is_float/is_numeric won't work, because is_float doesn't accept request parameters (which are strings) and is_numeric will accept something like "+.1e0" which is not what you want. The reliable way is to use regular expression for validation, for example
$is_decimal = preg_match('/^\d+(\.\d+)?$/', $some_string);
the expression may vary depending on your needs. For example, the above will also accept "000.00" or "111111111111111".
stereofrog
2010-02-09 10:00:18
-1 `if ((float)$a==$a)` would be acceptable, but not regular expressions
soulmerge
2010-02-09 10:04:27
@soulmerge: you didn't read my post correctly, i'm afraid. Both functions would accept "+.1e0" which is hardly "decimal"
stereofrog
2010-02-09 10:28:40
A:
Answers for english locale have already been posted. The NumberFormatter::parse() takes care of other locales, if you need such behaviour:
$formatter = new NumberFormatter('de-DE', NumberFormatter::PATTERN_DECIMAL);
if ($formatter->parse($value) !== false) {
# A correct numeric value in german locale, like '12.345,00001'
}
soulmerge
2010-02-09 10:02:38