== compares byte-wise equality for strings (UTF-8 sequences). For normalized Unicode text, consider unicode/norm before comparing.
if s1 == s2 {
// identical UTF-8 bytes
}
Use strings.Compare(a, b) returning -1/0/1, or relational operators < etc. on strings for lexicographic byte order (not always linguistic sort order).
For locale-aware sorting, use golang.org/x/text/collate or a dedicated library — not plain < on arbitrary user text.
import "strings"
strings.EqualFold("Go", "go") // true
strings.HasPrefix(s, "http://")
strings.HasSuffix(s, ".go")
strings.Contains(s, "needle")
strings.Intern (available in newer Go via weak/unique patterns) or manual maps reduce memory for repeated string keys — only when profiling shows duplication cost.