Introduction to Ethereum Smart Contract Development with Solidity (Part 2)

Ethereum is all the rage right now, promising one world computer that anyone can deploy arbitrary code (known as smart contracts) to. But if you actually try to get started writing your own smart contracts, you might find the entire ecosystem a little tricky to wrap your head around.

This is Part 2 of an ongoing series that walks through how to architect, code, and deploy Ethereum Smart Contracts with Solidity.

In this episode, we show how to create custom data types inside an Ethereum smart contract, and how to store those structures inside the state of a smart contract. We also build a UI for the Smart Contract in Javascript and show how to use the Web3 javascript library to query data about the deployed contract. You don't want to miss it.

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If you like these videos, feel free to send Ether donations to 0xEe82DDb350f48dd5712d54072172AA1A97c677C8

[victornaut]

Jordan you're like the Deadpool of web dev.

[patrickcollins]

in for loops, you should always store the length separately because if you do it in the loop arguments like you did at 13:00, it will result in the length being calculated for every iteration cycle which is wasteful. So it's always better to do: uint length = persons.length; for (uint i = 0; i < length; i++) { ... }

[peterwang]

This is really cool for people to know how powerful ethereum smart contract can use in real world. Thank you very much.

[angreeee]

i have programmed in dozens of languages and I can tell you 1 thing - solidity is a mess! Thank you guys for those tutorials.

[merunasg]

I love the speed and energy of these videos! Also you are teaching some complex concepts really well. What I want to see next is how would you deploy the contract + ui to a live website on the live ethereum homestead using IPFS. Because I think that's the best way to create dapp.

[saurabhjain]

awesome looking for part 3, that has events and

[Badmanji]

Awesome guys, made life simple in Ethereum work.

[HOkayson]

Just wanted to say a HUGE thank you for both part 1 and part 2! I just struggled through getting to know Solidity and the deployment model in the past few days using geth and a local ethereum testnet blockchain and that was...messy. Truffle + ethereumjs-testrpc + React is so much simpler and now I can really get down to what I want to do - i.e. write a more complex smart contract. I'm now subbed, anywhere you guys take donations so I can pass on a few £ for beer money? Looking forward to part 3!

[dabruhce]

Awesome videos. great starting point on working with ethereum.

[tuberajarajan]

Thanks Jordan 👍 great work, glad if you publish more videos on eth;

[mastery]

Im having some struggles while deploying my code. it says some attrs are removed on the truffle version im using. like constant.

[hounddog]

Thanks for this great tutorial! I learned a lot.

[prashanthkumar]

You guys are awesome!! :) Excellent tutorial

[jun]

Having independent React app and manually set web3 to talk to testrpc is easier than integrate react/webpack to truffle you think?

[RaghunandanMudadla]

can i know when the part 3 will be streamed?

[TheMichael]

While running the Dapp, it does not allow me to call the contract functions in JS. The message error is:

TypeError: Cannot read property 'match' of undefined

[michaeljayarizala]

Does anyone know how I can run such program on my own website? If I'm correct, the testrpc address localhost:8545 means that I am deploying the contract locally on my pc as being part of a private blockchain, right? So if I would want to actually deploy the contract on the actual ethereum node or the eth blockchain itself, would I just have to replace the localhost:8545 in Web3 with the actual URL? I am not totally familiar with this yet, but I really want to learn to develop my own smart contract. Thanks!

[twalter]

When I try to run the peopleContract.getPeople() method I get the following error: Cannot read property 'match' of undefined

peopleContract.address, people.Contract.abi etc. all work fine but my methods throw errors. Is it because of an update? When I use truffle console I need to do: => instance.getPeople()); However if I try a promise: instance.getPeople() }); I get .then is not a function.

Please help because it's confusing the hell out of me :)

[karelwinderickx]

Nice! This is really helping me getting forward with smart contracts and truffle. Will you upload part 3 soon? ;-)

[alfilax]

I have truffle v3.2.4. When I print "People.deployed().address" PowerShell writes undefined. The same is with "People.deployed().abi". What could be the problem here? Contract was properly compiled and migrated.