laravel中的dd是不是函数，用法是什么

在laravel中，dd()属于laravel辅助函数；dd函数用于输出给定的值并结束脚本运行，可以打印laravel中的所有变量，语法为“dd($value1,$value2...)”。

本文操作环境：Windows10系统、Laravel6版、Dell G3电脑。

laravel中dd属于函数吗

dd 函数输出给定的值并结束脚本运行：

dd($value);
dd($value1, $value2, $value3, ...);

示例PHP全局使用Laravel辅助函数dd：

全局 composer.json

"require": {
  "squizlabs/php_codesniffer": "*",
  "fxp/composer-asset-plugin": "^1.4",
  "symfony/var-dumper": "3.3.16"
}

配置PHP.ini

auto_prepend_file = "C:UsersMSAppDataRoamingComposervendorautoload.php"

更新Composer

composer global update

更新后重启apache就可以全局使用函数 dump()

dd() 方法

全局 composer.json

# 新增 autoload
"autoload": {
  "files": [
    "D:/web/php/debugHelper.php"
  ]
}

新建 debugHelper.php

# install symfony/var-dump to your project
# composer require symfony/var-dumper
 
// use namespace
use ComponentVarDumperClonerVarCloner;
use ComponentVarDumperDumperCliDumper;
use ComponentVarDumperDumperHtmlDumper as SymfonyHtmlDumper;
 
/**
 * Class HtmlDumper
 */
class HtmlDumper extends SymfonyHtmlDumper
{
  /**
大专栏 PHP 全局使用 Laravel 辅助函数 ddnt">   * Colour definitions for output.
   *
   * @var array
   */
  protected $styles = [
    'default' => 'background-color:#fff; color:#222; line-height:1.2em; font-weight:normal; font:12px Monaco, Consolas, monospace; word-wrap: break-word; white-space: pre-wrap; position:relative; z-index:100000',
    'num' => 'color:#a71d5d',
    'const' => 'color:#795da3',
    'str' => 'color:#df5000',
    'cchr' => 'color:#222',
    'note' => 'color:#a71d5d',
    'ref' => 'color:#a0a0a0',
    'public' => 'color:#795da3',
    'protected' => 'color:#795da3',
    'private' => 'color:#795da3',
    'meta' => 'color:#b729d9',
    'key' => 'color:#df5000',
    'index' => 'color:#a71d5d',
  ];
}
 
/**
 * Class Dumper
 */
class Dumper
{
  /**
   * Dump a value with elegance.
   *
   * @param mixed $value
   * @return void
   */
  public function dump($value)
  {
    if (class_exists(CliDumper::class)) {
      $dumper = 'cli' === PHP_SAPI ? new CliDumper : new HtmlDumper;
      $dumper->dump((new VarCloner)->cloneVar($value));
    } else {
      var_dump($value);
    }
  }
}
 
if (! function_exists('dd')) {
  /**
   * Dump the passed variables and end the script.
   *
   * @param mixed
   * @return void
   */
  function dd(...$args)
  {
    foreach ($args as $x) {
      (new Dumper)->dump($x);
    }
    die(1);
  }
}
 
if (! function_exists('dda')) {
  /**
   * Dump the passed array variables and end the script.
   *
   * @param mixed
   * @return void
   */
  function dda(...$args)
  {
    foreach ($args as $x) {
      (new Dumper)->dump($x->toArray());
    }
    die(1);
  }
}