go语言怎么比较字符串

func Equal(s1, s2 string) bool {  return s1 == s2 }  // 2-使用 compare 比较——区分大小写 func Compare(s1, s2 string) bool {  return strings.Compare(s1, s2) == 0 // }   //3-EqualFold 比较——不区分大小写. case-fold 即大小写同一处理 func EqualFold(s1, s2 string) bool {  return strings.EqualFold(s1, s2) }  // 使用等号比较——忽略大小写 func Equal2(s1, s2 string) bool {  return strings.ToLower(s1) == strings.ToLower(s2) }  // 使用 compare 比较——不区分大小写 func Compare2(s1, s2 string) bool {  return strings.Compare(strings.ToLower(s1), strings.ToLower(s2)) == 0 }   func StringCompareTest() {  fmt.Println("== 区分大小写", Equal("go", "Go"))  //false  fmt.Println("== 忽略大小写",Equal2("go", "Go"))  //true  fmt.Println("compare 区分大小写",Compare("go", "Go")) //false  fmt.Println("compare 忽略大小写",Compare2("go", "Go")) //true  fmt.Println("EqualFold 忽略大小写",EqualFold("go", "Go")) // true }

package test  import (  "../str"  "testing" )  func BenchmarkStrEqual(b *testing.B) {  for i := 0; i < b.N; i++ {   str.Equal("go", "Go")  } } func BenchmarkStrEqual2(b *testing.B) {  for i := 0; i < b.N; i++ {   str.Equal2("go", "Go")  } } func BenchmarkStrCompare(b *testing.B) {  for i := 0; i < b.N; i++ {   str.Compare("go", "Go")  } } func BenchmarkStrCompare2(b *testing.B) {  for i := 0; i < b.N; i++ {   str.Compare2("go", "Go")  } } func BenchmarkStrEqualFold(b *testing.B) {  for i := 0; i < b.N; i++ {   str.EqualFold("go", "Go")  } }

package strings  // Compare returns an integer comparing two strings lexicographically. // The result will be 0 if a==b, -1 if a < b, and +1 if a > b. // // Compare is included only for symmetry with package bytes. // It is usually clearer and always faster to use the built-in // string comparison operators ==, <, >, and so on. func Compare(a, b string) int {  // NOTE(rsc): This function does NOT call the runtime cmpstring function,  // because we do not want to provide any performance justification for  // using strings.Compare. Basically no one should use strings.Compare.  // As the comment above says, it is here only for symmetry with package bytes.  // If performance is important, the compiler should be changed to recognize  // the pattern so that all code doing three-way comparisons, not just code  // using strings.Compare, can benefit.  if a == b {   return 0  }  if a < b {   return -1  }  return +1 }

// EqualFold reports whether s and t, interpreted as UTF-8 strings, // are equal under Unicode case-folding, which is a more general // form of case-insensitivity. func EqualFold(s, t string) bool {  for s != "" && t != "" {   // Extract first rune from each string.   var sr, tr rune   if s[0] < utf8.RuneSelf {    sr, s = rune(s[0]), s[1:]   } else {    r, size := utf8.DecodeRuneInString(s)    sr, s = r, s[size:]   }   if t[0] < utf8.RuneSelf {    tr, t = rune(t[0]), t[1:]   } else {    r, size := utf8.DecodeRuneInString(t)    tr, t = r, t[size:]   }    // If they match, keep going; if not, return false.    // Easy case.   if tr == sr {    continue   }    // Make sr < tr to simplify what follows.   if tr < sr {    tr, sr = sr, tr   }   // Fast check for ASCII.   if tr < utf8.RuneSelf {    // ASCII only, sr/tr must be upper/lower case    if 'A' <= sr && sr <= 'Z' && tr == sr+'a'-'A' {     continue    }    return false   }    // General case. SimpleFold(x) returns the next equivalent rune > x   // or wraps around to smaller values.   r := unicode.SimpleFold(sr)   for r != sr && r < tr {    r = unicode.SimpleFold(r)   }   if r == tr {    continue   }   return false  }   // One string is empty. Are both?  return s == t }