til / use valueAs* on inputs
If you want to get the value of an input as a number or a date you can easily parse the value of a type="text" input. However, there's an easier solution by using valueAsNumber or valueAsDate. The attributes are only available for certain input types. The attributes return NaN if not available or if the value is invalid.
Browser support is great, valueAsNumber is supported by all browsers (even IE) and valueAsDate is supported by all browsers except IE.
// This will always return NaN since valueAsNumber
// is not available on text inputs
<input type="text" onChange={e => console.log(e.target.valueAsNumber)} />
// Return the value as an integer or a float
// depending on the input's step attribute
<input type="number" onChange={e => console.log(e.target.valueAsNumber)} />
// Return the date as a UNIX timestamp, i.e. new Date().getTime()
<input type="date" onChange={e => console.log(e.target.valueAsNumber)} />
// Return the date as a JS Date object
<input type="date" onChange={e => console.log(e.target.valueAsDate)} />