Go 字符串比较(go字符串比较大小)
golang 字符串比较
字符串比较， 可以直接使用 == 进行比较， 也可用用 strings.Compare 比较
go 中字符串比较有三种方式：
==比较strings.Compare比较strings.EquslFold比较
#### 代码示例 ```go fmt.Println("go"=="go") fmt.Println("GO"=="go") fmt.Println(strings.Compare("GO","go")) fmt.Println(strings.Compare("go","go")) fmt.Println(strings.EqualFold("GO","go")) 复制代码上述代码执行结果如下：
true false -1 0 true 复制代码
Compare 和 EqualFold 区别
EqualFold是比较UTF-8编码在小写的条件下是否相等，不区分大小写
// EqualFold reports whether s and t, interpreted as UTF-8 strings, // are equal under Unicode case-folding. func EqualFold(s, t string) bool 复制代码
要注意的是
Compare函数是区分大小写的，==速度执行更快
// 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 复制代码
忽略大小写比较
有时候要忽略大小写比较, 可以使用strings.EqualFold 字符串比较是否相等
源码实现
// 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 } 复制代码通过源码可看到 if 'A' <= sr && sr <= 'Z' && tr == sr+'a'-'A' 可以看到不区分大小写的实现。
看个完整测试代码：
// Golang program to illustrate the // strings.EqualFold() Function package main // importing fmt and strings import ( "fmt" "strings" ) // calling main method func main() { // case insensitive comparing and returns true. fmt.Println(strings.EqualFold("Geeks", "Geeks")) // case insensitive comparing and returns true. fmt.Println(strings.EqualFold("computerscience", "computerscience")) } 复制代码执行结构
true true
作者：banjming
链接：https://juejin.cn/post/7032887851066851342