PHP致命錯誤：未捕獲的錯誤：類「的Symfony \分量\控制檯\應用程序」沒有找到

Question

我想用PHP創建一個簡單的命令行應用程序，但我不斷收到：

PHP Fatal error: Uncaught Error: Class 'Symfony\Component\Console\Application' not found in /Applications/MAMP/htdocs/newcli/dan.php:6 
Stack trace: 
#0 {main} 
    thrown in /Applications/MAMP/htdocs/newcli/dan.php on line 6 

Fatal error: Uncaught Error: Class 'Symfony\Component\Console\Application' not found in /Applications/MAMP/htdocs/newcli/dan.php:6 
Stack trace: 
#0 {main} 
    thrown in /Applications/MAMP/htdocs/newcli/dan.php on line 6 

我在做什麼錯？我的PHP版本：PHP 7.1.0RC6 (cli) (built: Nov 9 2016 04:45:59) (NTS)

dan.php：

#! usr/bin/env php 
<?php use Symfony\Component\Console\Application; 

require 'vendor/autoload.php'; 

$app = new Application('Task App', '1.0'); 

$app->add(new Acme\ShowCommand()); 
$app->run(); 

Answer 1

的use聲明必須放在require 'vendor/autoload.php'

#! usr/bin/env php 
<?php 

require 'vendor/autoload.php'; 

use Symfony\Component\Console\Application; 

$app = new Application('Task App', '1.0'); 

$app->add(new Acme\ShowCommand()); 
$app->run();