fmt printing

Canonical guidance

• choose the simplest fmt API that matches the job
• use verbs intentionally
• implement String() only when the string form is genuinely useful

Use when

• building human-readable messages
• debugging values locally
• implementing textual representations

Avoid

• fmt.Sprintf for trivial concatenation
• production logging with scattered fmt.Printf
• guessing verbs until output “looks right”

Preferred pattern

msg := fmt.Sprintf("user %q not found", id)

Anti-pattern

• fmt.Printf("%s", someStruct)

Explanation: This is tempting because many values print somehow, but wrong verbs hide bugs and produce misleading output.

Why

• formatting code is small, high-frequency, and easy to get subtly wrong