title: How to check if Ethereum address is valid in solidity?
body: <p>Is there a way to check if the ethereum address is valid in solidity ? I think I might have found a way in web3js library on utils, but want to know if this method is possible on solidity.</p>
  <p>And how can I use solidity to know the difference between account addresses and smart contract address ?</p>
  <p>Your help will be highly appreciated (still new guys)… Thanks in advance.</p>