简单介绍Go 字符串比较的实现示例

本文主要介绍了Go 字符串比较的实现示例，主要包括三种比较方式，具有一定的参考价值，感兴趣的可以了解一下

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"))

上述代码执行结果如下：

true
false
-1
0
true

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

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

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'