Question

我正在尝试将变量从控制器传递到视图，但是它显示以下消息：

未定义的变量。

控制器

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class QuizController extends Controller
{
public function getUrl($url = null) {
    $bandeira = '1';
    $bandeira2 = '2';

    if ($url == '1') {

        return view('quiz')->with($bandeira);

    } elseif ($url == '2') {

        return view('quiz')->with($bandeira2);

    } else {
        return view('home');

    }
  }
}

查看

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />

<title>Copa do Mundo 2018</title>

<link rel="stylesheet" type="text/css" href="css/style.css" />
</head>

<body>

<div id="page-wrap">

<h1>Quiz Copa do Mundo 2018</h1>

<form action="grade.php" method="post" id="quiz">

    <ol>

        <li>

            <h3> ?</h3>
            @if($bandeira == '1')
                <img src="{{ asset('img/espanha.jpg') }}" alt=""/>
            @elseif($bandeira == '2') 
                <img src="{{ asset('img/argentina.jpg') }}" alt=""/>
            @endif

Answer 1

以这种方式传递信息时，数据应为具有键/值对的数组。然后，您可以在视图内部使用其对应的键（例如
<?php echo $key; ?>）访问每个值。

更正您的代码：

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class QuizController extends Controller
{
public function getUrl($url = null) {

   $data_to_view['bandeira'] = url;

    if ($url != null) {

        return view('quiz')->with($data_to_view);

    } else {
        return view('home');

    }
  }
}

您认为：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />

<title>Copa do Mundo 2018</title>

<link rel="stylesheet" type="text/css" href="css/style.css" />
</head>

<body>

<div id="page-wrap">

<h1>Quiz Copa do Mundo 2018</h1>

<form action="grade.php" method="post" id="quiz">

    <ol>

        <li>

            <h3> ?</h3>
            @if($bandeira == '1')
                <img src="{{ asset('img/espanha.jpg') }}" alt=""/>
            @elseif($bandeira == '2') 
                <img src="{{ asset('img/argentina.jpg') }}" alt=""/>
            @endif

Answer 2

这样写变量

   $bandeira['bandeira'] = 1;
   return view('quiz')->with($bandeira);

Answer 3

我认为您应该像这样编写getUrl方法 return view('home', ['bandeira' => $url]);，不需要if语句

Answer 4

更改您的查看页面

const target = 1234; // count the number of digits

function numDigits(num, count=0){
     let div10 = count;
     div10 += 1;

     if(Math.floor(num / 10) < 1){
          console.log(`Entered the end and div10 is ${div10}`);
          return div10; // returning undefined
     }

     let curr = Math.floor(num / 10);
     console.log(`Bottom of call and dividing ${curr}`);

     return numDigits(curr, div10); // HERE

}

console.log(numDigits(target));

我认为这对您有帮助

未定义的变量（在视图中找不到变量）

控制器

查看

4 个答案: