开关或操作员编译器错误

I have following code that compiler complain.

switch req.Method {
        case "POST" || "PUT" || "DELETE":
            if req.Header.Get("Content-Type") != "application/json" {
                return handleErr(req)
            }
    }

Compiler error message

..\..\controllersoutes\header.go:59: invalid operation: "POST" || "PUT" (operator || not defined on string)

Do I use OR operator in wrong way?

Just use comma , instead of ||.

case "POST", "PUT", "DELETE":

See switch statement reference.