I have a set of string numbers having decimals, for example: 23.456
, 9.450
, 123.01
... I need to retrieve the number of decimals for each number, knowing that they have at least 1 decimal.
In other words, the retr_dec()
method should return the following:
retr_dec("23.456") -> 3
retr_dec("9.450") -> 3
retr_dec("123.01") -> 2
Trailing zeros do count as a decimal in this case, unlike in this related question.
Is there an easy/delivered method to achieve this in Javascript or should I compute the decimal point position and compute the difference with the string length? Thanks
function decimalPlaces(num) {
var match = (''+num).match(/(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/);
if (!match) { return 0; }
return Math.max(
0,
// Number of digits right of decimal point.
(match[1] ? match[1].length : 0)
// Adjust for scientific notation.
- (match[2] ? +match[2] : 0));
}
The extra complexity is to handle scientific notation so
decimalPlaces('.05') 2 decimalPlaces('.5') 1 decimalPlaces('1') 0 decimalPlaces('25e-100') 100 decimalPlaces('2.5e-99') 100 decimalPlaces('.5e1') 0 decimalPlaces('.25e1') 1