Hello World

Program Code

This program will log our hello world message into program's on-chain transaction log. We will simply use msg!() macro for logging the hello world.

To initialize the project, simply run:

anchor init hello-world

Program's Code

Let's wirte our first hello world program a.k.a smart contract in anchor or just copy-pasta the following code into your lib.rs file 😉.

use anchor_lang::prelude::*;
declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
#[program]
pub mod hello_world {
    use super::*;
    pub fn hello_world(_ctx: Context<Initialize>) -> Result<()> {
        msg!("Hello world, from solana smart contract");
        Ok(())
    }
}
#[derive(Accounts)]
pub struct Initialize {}

Now compile and build this program, by simply running:

anchor build

Test

Now It's time to write a test for our program! Copy-pasta the following code into your hello-world.ts file in tests folder in the root directory.

import * as anchor from "@project-serum/anchor";
import { Program } from "@project-serum/anchor";
import { HelloWorld } from "../target/types/hello_world";


describe("hello-world", () => {
  anchor.setProvider(anchor.AnchorProvider.env());
  const program = anchor.workspace.HelloWorld as Program<HelloWorld>;


  it("Mic testing - Hello world", async () => {
    const tx = await program.methods.helloWorld().rpc();
    console.log("Your transaction signature", tx);
  });
});

Deployment 🎉

Time to deploy and test our first hello world smart contract, yay!

We are going to deploy on devnet. Here is our deployment checklist 🚀

1. Run anchor build. Your program keypair is now in target/deploy. Keep this keypair secret 🤫.
2. Run anchor keys list to display the keypair's public key and copy it into your declare_id! macro at the top of lib.rs.
3. Run anchor build again. This step is necessary to include the new program id in the binary.
4. Change the provider.cluster variable in Anchor.toml to devnet.
5. Run anchor deploy
6. Run anchor test

On-Chain Result

> Program logged: "Instruction: HelloWorld"
> Program logged: "Hello world, from solana smart contract"
> Program consumed: 452 of 200000 compute units
> Program returned success

Program's transaction log