[Ethereum] How to check for 0 address with web 3

There is an isAddress() method from web3.utils, you need to use version one or following version (v1-beta, now default and latest via npm)

Example:

web3.utils.isAddress(address)

Solidity Docs link: http://web3js.readthedocs.io/en/1.0/web3-utils.html?highlight=isValidAddress#isaddress

By default, truffle uses the first account but in truffle.js you can specify the account address in the from property:

module.exports = {
  networks: {
    development: {
      host: 'localhost',
      port: 8545,
      network_id: '*', 
      from: '0x0c439ff0170Ab7d7Ef55f2993554eede7321c9b7'
    }
  }
}

If you want to deploy to a network other than localhost then you need to import a wallet provider and pass it your mnemonic.

Here's an example where the mnemonic is read from an environment variable and the provider is set to rinkeby testnet:

const HDWalletProvider = require('truffle-hdwallet-provider')

const mnemonic = process.env.MNEMONIC

module.exports = {
  networks: {
    development: {
      host: "localhost",
      port: 8545,
      network_id: "*" 
    },
    rinkeby: {
      provider: new HDWalletProvider(mnemonic, 'https://rinkeby.infura.io'),
      network_id: '*',
      gas: 4500000,
      gasPrice: 25000000000
    }
  }
}