strs

var inputs = []string{
	"XiaoMei", "xiaoMei", "HTTPStatus", "You123", "PriceP", "4sPrice", "Price4s", "goodHTTP",
	"ILoveGolangAndJSONSoMuch",
}
for i := range inputs {
	fmt.Println(CamelToSnake(inputs[i]))
}

Output:

xiao_mei
xiao_mei
http_status
you123
price_p
4s_price
price4s
good_http
i_love_golang_and_json_so_much

fmt.Println(FirstLetterToLower("abc"))
fmt.Println(FirstLetterToLower("Abc"))

Output:

abc
abc

fmt.Println(FirstLetterToUpper("Abc"))
fmt.Println(FirstLetterToUpper("abc"))

Output:

Abc
Abc

var inputs = []string{"xiao_mei", "http_status", "you123", "price_p"}
for i := range inputs {
	fmt.Println(SnakeToCamel(inputs[i]))
}

Output:

XiaoMei
HttpStatus
You123
PriceP