Cannot use uppercase address in isAddress

[sc0Vu]

I've try many times to use uppercase address in isAddress, but it always return false.
Test address input 0XCA35B7D915458EF540ADE6068DFE2F44E8FA733C.
After trace the source code, I found the els if didn't work (it return false in first if).
So the uppercase address cannot using...

https://github.com/ethereum/web3.js/blob/bacd46e94e31ec5d4d70c4396f42eb6ff6146a20/packages/web3-utils/src/utils.js#L81

[taylorjdawson]

Can you include a code snippet of how you are using the isAddress method?

[eepstein]

Why isn't this just using the isValidAddress() function from https://github.com/ethereumjs/ethereumjs-util/blob/master/docs/index.md ?
Why hand-roll the logic for this when there's a package that implements the standard?

[eepstein]

@sc0Vu from what I understand, case can be significant in ETH addresses. In particular, the default is that addresses are all lowercase, and that if addresses contain a mix of upper and lower case then the case of the A-F digits is providing a kind of in-line checksum of the address to help prevent typos.

So... not working with uppercase hex digits may be by design. For details on the clever mixed-case checksum, see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-55.md