Php Laravel创建项目时出错

我是拉威尔的新人 我在ubuntu中安装了composer和laravel 但是当我插入

composer创建项目laravel/laravel{projectname}

来创建项目
这些错误让我明白了

 Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - phpunit/phpunit 7.5.x-dev requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.5.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.5.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.5 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.4 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.3 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.2 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.4.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.5 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.4 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.3 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.2 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.3.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.7 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.6 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.5 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.4 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.3 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.2 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.2.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.5 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.4 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.3 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.2 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.1.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.0.3 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.0.2 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.0.1 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - phpunit/phpunit 7.0.0 requires ext-dom * -> the requested PHP extension dom is missing from your system.
    - Installation request for phpunit/phpunit ^7.0 -> satisfiable by phpunit/phpunit[7.0.0, 7.0.1, 7.0.2, 7.0.3, 7.1.0, 7.1.1, 7.1.2, 7.1.3, 7.1.4, 7.1.5, 7.2.0, 7.2.1, 7.2.2, 7.2.3, 7.2.4, 7.2.5, 7.2.6, 7.2.7, 7.3.0, 7.3.1, 7.3.2, 7.3.3, 7.3.4, 7.3.5, 7.4.0, 7.4.1, 7.4.2, 7.4.3, 7.4.4, 7.4.5, 7.5.0, 7.5.1, 7.5.x-dev].

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我在google上搜索了我的这个问题，但是我找不到任何有用的东西

为了实现这一点，你应该安装php xml

sudo apt-get install php-xml

这将安装php xml（取决于您使用的php版本）。我认为你也可以做到以下几点：

---

sudo apt get install php7.0-xml

为了实现这一点，您应该安装php xml

sudo apt-get install php-xml

这将安装php xml（取决于您使用的php版本）。我认为你也可以做到以下几点：

---

sudo apt get install php7.0-xml

的可能重复给了我一个错误，没有这样的包给了我一个错误，没有这样的包