: Hello World

Our first smart-contract will return the classic “Hello World” message.

Define a public function called “hello-world”.

 

(define-public (hello-world)

Returns “Hello World” with a status ok.

 

    (ok "Hello World")
)

Before we can run the smart-contract, we need to set our Clarinet workspace.

First create our workspace.

 

$ clarinet new example
Creating directory example
Created file example/contracts
Created file example/settings
Created file example/tests
Created file example/Clarinet.toml
Created file example/settings/Mainnet.toml
Created file example/settings/Testnet.toml
Created file example/settings/Devnet.toml
Created file example/.vscode
Created file example/.vscode/settings.json
Created file example/.vscode/tasks.json
Created file example/.gitignore

Then create our contract.

 

$ clarinet contract new hello-world
Updated Clarinet.toml with contract hello-world

Put the source code in the contract (located at contracts/hello-world.clar).

Now we have our Clarinet workspace set up we can load our contract into the REPL.

 

$ clarinet poke
clarity-repl v0.21.0
Enter "::help" for usage hints.
Connected to a transient in-memory database.

List of contracts and callable functions.

 

Contracts
+---------------------+------------------+
| Contract identifier | Public functions |
+---------------------+------------------+
| address.hello-world | (hello-world)    |
+---------------------+------------------+

Wallets loaded in from settings/Devnet.toml, balances listed in uSTX.

 

Initialized balances
+--------------------+-----------------+
| Address            | STX             |
+--------------------+-----------------+
| address (deployer) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_1) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_2) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_3) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_4) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_5) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_6) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_8) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_7) | 100000000000000 |
+--------------------+-----------------+
| address (wallet_9) | 100000000000000 |
+--------------------+-----------------+

Now that we’re in the REPL, we can call the public functions/contracts listed above.

For example here’s how we can call the hello-world function from our .hello-world contract.

 

$ (contract-call? .hello-world hello-world)
(ok "Hello World")

The process for setting up our Clarinet workspace will be the same for the rest of our smart-contracts.

Next example: SIP-10 (Tokens).

by Linden | source | license