Let's say we have 2 smart contracts. A and B. A calls B, and B throws an error. What happen in A? Not sure? haha, that's a tricky one! Actually it depends on how B was called. If B was called the normal way, the whole transaction get reverted: contract A {…

https://youtu.be/-5j6Ho0Bkfk ERC20 tokens allow you to create your own coin inside Ethereum.  They are used in many projects to represent financial assets, in-game assets, collectible, and other kind of assets. At some point in your project, you will probably need to interact with them. And most often, you will need to…

https://youtu.be/_Nvl-gz-tRs Sending Ether between smart contracts is very important. After all, it's because smart contracts can do financial transactions that they are so powerful. But surprisingly there are a few caveats when you want to send ether from a smart contract: Transfer units are in wei (10^-18 ether), not ether…

https://youtu.be/MPBOnChpi0c Solidity arrays... are like Javascript arrays, right? Nope.. In Solidity: Arrays can only contain data of the same type (ex: arrays of integers, array of booleans, but not arrays of integers AND booleans..) Arrays can be in storage, or in memory (persistent and non-persistent) You can use the `push()`…

When you develop an Ethereum Dapp, once you have the frontend and the smart contract, you need to connect them together. This is not easy. Fortunately, Web3 is here to save you! Wait... not so fast... Actually, it's not that easy to learn how to use Web3: Many Web3 tutorials…

Here is the scene: You are about to use your Ethereum address to do some trading, or to send some Ether to someone. You connect to your wallet and check your balance... It's empty!! What?! You were supposed to have 100 Ether in it.. what happened? Have you been hacked?…