length
is a property, not a method. You can't call it, hence you don't need parenthesis ()
:
function getlength(number) {
return number.toString().length;
}
UPDATE: As discussed in the comments, the above example won't work for float numbers. To make it working we can either get rid of a period with String(number).replace('.', '').length
, or count the digits with regular expression: String(number).match(/\d/g).length
.
In terms of speed potentially the fastest way to get number of digits in the given number is to do it mathematically. For positive integers there is a wonderful algorithm with log10
:
var length = Math.log(number) * Math.LOG10E + 1 | 0; // for positive integers
For all types of integers (including negatives) there is a brilliant optimised solution from @Mwr247, but be careful with using Math.log10
, as it is not supported by many legacy browsers. So replacing Math.log10(x)
with Math.log(x) * Math.LOG10E
will solve the compatibility problem.
Creating fast mathematical solutions for decimal numbers won't be easy due to well known behaviour of floating point math, so cast-to-string approach will be more easy and fool proof. As mentioned by @streetlogics fast casting can be done with simple number to string concatenation, leading the replace solution to be transformed to:
var length = (number + '').replace('.', '').length; // for floats