Function parseHex

parseHex(hex: string): number | null
Parses a hex string (with or without 0x prefix) to number. Returns null if string is not valid hex.
Parameters
- hex: string
Returns number | null
Example
```
parseHex("FF")     → 255
```
Example
```
parseHex("0x1F4") → 500
```
Example
```
parseHex("ZZ")    → null
```
Example
```
parseHex("")      → null
```
- Defined in utils/hex.ts:64