We’ll start our Dapp by writing the smart contract that acts as the back-end logic and storage.
1.
Create a new file named Adoption.sol in the contracts/ directory.
2.
Copy the following code:
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pragma solidity ^0.5.0;contract Adoption {
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address[16] public adopters; // Adopting a pet
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function adopt(uint petId) public returns (uint) {
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// check that petId is in range of our adopters array
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require(petId >= 0 && petId <= 15); // add the address who called this function to our adopter array
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adopters[petId] = msg.sender; // return the petId provided as a confirmation
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return petId;
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} // Retrieving the adopters
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function getAdopters() public view returns (address[16] memory) {
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return adopters;
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}
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}
Copied!
Note: Code from Truffle’s Pet-Shop tutorial — if you want to look deeper into the Solidity code, they slowly go through the Truffle link explaining the details.
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Compiling
Solidity is a compiled language, meaning we need to compile our Solidity to bytecode for the Ethereum Virtual Machine (EVM) to execute. Think of it as translating our human-readable Solidity into something the EVM understands.
TomoChain is EVM-compatible, which means that every contract written in Ethereum can be seamlessly ported to TomoChain without effort
In a terminal, make sure you are in the root of the directory that contains the Dapp and type: