Control flow

if, with an optional head start

Go's if looks familiar — but no parentheses around the condition, and the braces are required even for one line. The bonus: if can run a short init statement first, separated by a semicolon:

    // price is in scope here (and in the else)
}

That declares price, then tests it. price lives only inside the if/else — a tidy way to scope a value to exactly where it's used. You'll see this constantly with the err pattern: if err := doThing(); err != nil { ... }.