任意の文字列を Ethereum ブロックチェーンに書き込むやつ

要MetaMask

code:demo.js

$(document.body).append('<h1>Write your words on Ethereum Blockchain</h1>')

$(document.body).append('<p>address: <input type="text" size="70" id="address">')

$(document.body).append('<p>your words: <input type="text" size="70" id="text">')

$(document.body).append('<p><button id="submit">submit</button></p>')

var web3js;

if (typeof web3 !== 'undefined') {

console.log("Use MetaMask")

web3js = new Web3(web3.currentProvider)

} else {

alert("Please use MetaMask")

}

$('#submit').on('click', function(event) {

let address = $('#address').val()

let text = $('#text').val()

let result = Web3.utils.isAddress(address)

if (result == true && text != "") {

let data = Web3.utils.utf8ToHex(text)

console.log(data)

web3.eth.sendTransaction({

to:address,

value:0,

gas:200000,

data: data

}, function(error, hash){

alert("Transaction Sent. " + ethscanUrl)

})

}

})