String construction

Canonical guidance

• use + for a few local concatenations
• use fmt.Sprintf when formatting is the point
• use strings.Builder when assembling a string incrementally over several writes

Use when

• formatting messages
• generating text output
• reviewing small performance-sensitive string assembly

Avoid

• introducing strings.Builder for tiny fixed expressions
• using fmt.Sprintf when simple concatenation is clearer
• premature micro-optimization without a readability or measurement win

Preferred pattern

var b strings.Builder
b.WriteString(prefix)
b.WriteString(name)
return b.String()

Anti-pattern

• replacing every short a + b with a builder purely because it feels more performance-minded

Explanation: This is tempting because builders sound efficient, but for small local cases they often add ceremony without helping clarity.

Why

• Google’s best-practice guidance is unusually concrete here and fills a gap in the current corpus