Number conversion: just a number please
Converting something to a Number can be a puzzling experience in ECMAScript (ES). There are edge cases with weird results. For example Number(null)
or Number([])
return 0. Trying to convert a Symbol
will throw a TypeError
.
So here's a small utility (a class free object oriented factory) to convert input to the numbers one expects. It returns NaN
when conversion doesn't comply to our standards1 (so: [nr utility](null)
will return NaN
).
Notes:
- most edge cases are mitigated, not all.
- Number strings containing ',' (e.g.
0.42.toLocaleString("nl")
: '0,42') will also be converted. - By default the function from the the factory does not include 'converting'
Infinity
(to ... well ...Infinity
).
The embedded Stackblitz example compares the result of default (ES) conversion (Number(...)
) to conversion using the utility for a number of values.
1 Which may very well not be your standards, feel free to comment or modify the function
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