Strings

Canonical guidance

• strings are immutable
• bytes and runes solve different problems
• slicing a string operates on bytes, not characters

Use when

• text processing
• protocol fields
• log and error messages

Avoid

• indexing strings as if every character were one byte
• converting between string and []byte repeatedly without reason
• assuming all input is valid UTF-8

Preferred pattern

for _, r := range s {
	fmt.Println(r)
}

Anti-pattern

• slicing strings by byte offsets when the logic really cares about user-visible characters

Explanation: This anti-pattern is tempting because byte indexing is simple, but it breaks once multibyte UTF-8 input appears.

Why

• string handling bugs are often really byte-vs-rune bugs