Ledger LandISSUE #29 of 90

solidity · the contract language

BlockyVSDouble-Spend Dan

Blocky saysSolidity is the main smart-contract language — C/JS-like, compiled to EVM bytecode.

Solidity is statically-typed and curly-braced, purpose-built for the EVM. A contract declares state variables, functions, events, and modifiers. It's deceptively familiar but unforgiving: code is immutable once deployed, bugs can lose real money, and gas costs shape how you write. You write small, audited, well-tested contracts — not sprawling apps.

Power-ups you unlock

Statically-typed, C/JS-like, EVM-targeted
Contracts: state, functions, events, modifiers
Deployed code is usually immutable
Bugs cost real money → audit + test

Double-Spend Dan attacks — common mistakes

Treating Solidity like ordinary app code
Shipping un-audited contracts
Ignoring gas costs while coding

Boss battleWrite a minimal contract with one state variable and a setter.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre>contract Counter {
  uint public count;
  function inc() public { count += 1; }
}</pre></body></html>

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