HelloWorld

The code for the first chapter of the book : Blockchain by Example. this script creates an op_return output using bitcoinJs-lib as presented in the book.

instructions :

Firstly : send some bitcoins from a faucet website to n3CKupfRCJ6Bnmr78mw9eyeszUSkfyHcPy
Secondly : run node hello.js

P2SH or P2PKH :

you can use https://testnet.blockexplorer.com/api/txs/?address=2MsHsi4CHXsaNZSq5krnrpP4WShNgtuRa9U to determine online whether the transaction output is a P2SH or P2PKH

or by using https://api.blockcypher.com/v1/btc/test3/txs/0791521362528725683caedf998006cf68b1cd817be1694ef0daca265d9b4252?limit=50&includeHex=true

"outputs": [
    {
      "value": 1253185750,
      "script": "76a914b9172e192d2805ea52fa975847eea0657e38fef888ac",
      "spent_by": "7f3773696c100f75637f2130713ed5b4e5a747f00fb2250e0334a89bafaa5284",
      "addresses": [
        "mxPd583YeW6iw3cCgfrmrdcXKG6PLM2fBj"
      ],
      "script_type": "pay-to-pubkey-hash"
    },
    {
      "value": 110000000,
      "script": "76a914edcce89f510bf95606ec6a79cb28a745c039e22088ac",
      "spent_by": "d3e300c2f2eedf673ab544f4c2b09063353e618ab8a0c9444e931d0145e43ded",
      "addresses": [
        "n3CKupfRCJ6Bnmr78mw9eyeszUSkfyHcPy"
      ],
      "script_type": "pay-to-pubkey-hash"
    }
  ]