Question

如何将数据转换为string类型？我需要写下我需要的data文件，该文件不是变量，我该怎么做？

代码：

package main

import "os"
import "os/user"
import "encoding/json"

func main(){
    f, err := os.OpenFile("test.txt", os.O_APPEND|os.O_WRONLY, 0600)
    if err != nil {
        panic(err)
    }
    defer f.Close()

    cur, err := user.Current()
    if err != nil {

    } else {


        if _, err = f.WriteString(cur); err != nil {
        panic(err)
        }
    }
}

我不需要使用cur.Username字段。只有一个变量。

Answer 1

File.WriteString()期望string参数，但您尝试将cur传递给类型为*user.User的user.User，这是指向结构的指针。这显然是编译时错误。

type User struct { // Uid is the user ID. // On POSIX systems, this is a decimal number representing the uid. // On Windows, this is a security identifier (SID) in a string format. // On Plan 9, this is the contents of /dev/user. Uid string // Gid is the primary group ID. // On POSIX systems, this is a decimal number representing the gid. // On Windows, this is a SID in a string format. // On Plan 9, this is the contents of /dev/user. Gid string // Username is the login name. Username string // Name is the user's real or display name. // It might be blank. // On POSIX systems, this is the first (or only) entry in the GECOS field // list. // On Windows, this is the user's display name. // On Plan 9, this is the contents of /dev/user. Name string // HomeDir is the path to the user's home directory (if they have one). HomeDir string }是一个具有以下定义的结构：

Username

选择要输出到文件的内容，很可能是Name字段或string字段。这些是if _, err = f.WriteString(cur.Username); err != nil { panic(err) }类型的字段，因此您可以毫无问题地通过这些字段：

User

如果您想写出完整的if _, err = fmt.Fprintf(f, "%+v", cur); err != nil { panic(err) }结构，可以使用fmt包，方便的fmt.Fprint()或fmt.Fprintf()功能：

public function index(Request $request)
{
   // if param exists, call function from another controller
   if($request->has('callAnotherMethod')){
       return app('App\Http\Controllers\yourControllerHere')->index();
   }
   $comproducts = Comproduct::paginate(6);

   $items = Item::orderBy('name')->get();

   return view('computer', compact(['comproducts', 'items']));

}

错误：不能使用cur（type * user.User）作为f.WriteString参数中的类型字符串

1 个答案: