Hello Soroban

Let's create our first Soroban smart contract

#![no_std]
use soroban_sdk::{contract, contractimpl, Env, log};
 
#[contract]
pub struct HelloWorld;
 
#[contractimpl]
impl HelloWorld {
    /// Welcome to Soroban-by-example!
    ///
    /// The function logs a "Hello World" message to the Soroban environment.
    ///
    /// Have fun exploring Soroban!
    pub fn say_hello(env: Env) {
        log!(&env, "Hello World");
    }
}

Guide

#![no_std] This attribute prevents linking to the standard library, making the code lighter and more efficient for Soroban contracts. It's big so we save on size.

use soroban_sdk::{contract, contractimpl, Env, log} Imports stuffs from the Soroban SDK. Env is basic Soroban type, we need it because we can't use the Rust standard library.

#[contract] Marks the struct as a Soroban smart contract. Soroban smart contracts are defined as Rust structs.

#[contractimpl] Marks the implementation block as containing contract methods and transforms it to code that Soroban can evaluate directly

pub Marks a function as external, meaning it can be invoked outside of the context of the contract code itself.

Live Example