How to debug PHP functions with Symfony VarDumper?

How to use Symfony VarDumper to debug PHP functions? Installation: Install VarDumper via Composer. Usage: CLI: Use the var_dump() function to pass variables to VarDumper. Web requests: configure the DebugBundle and use the dump() function. Practical example: Debugging complex arrays: VarDumper presents array structures in a user-friendly format, showing their keys and values. Debugging Objects: VarDumper displays the class and private properties of an object, making it easy to view its status.

How to use Symfony VarDumper to debug PHP functions

Introduction

Symfony VarDumper is Powerful tool for debugging PHP functions and variables. It can present complex data structures in a user-friendly way and is easy to use with CLI or web requests.

Installation

Install VarDumper via Composer:

composer require symfony/var-dumper

Usage

CLI

In the CLI, variables can be passed to VarDumper using the var_dump() function:

var_dump($variable);

VarDumper will output the variable in a readable format.

Web Request

In order to use VarDumper in a Web request, you need to configure the DebugBundle:

# app/config/config.yml
framework:
    debug: true
    profiler:
        collect: true

Then, you can use it# in a controller or template ##dump() Function:

// 控制器
dump($variable);

// 模板
{{ dump(variable) }}

VarDumper Output will be displayed in the debug toolbar or page source code.

Practical case

Debugging complex array

If we have a complex array that needs to be debugged:

$array = [
    'name' => 'John Doe',
    'address' => [
        'street' => '123 Main Street',
        'city' => 'Anytown',
        'state' => 'CA',
    ],
];

Using VarDumper we can easily view the structure of the array:

var_dump($array);

will produce the following output:

array(2) {
  ["name"]=>
  string(7) "John Doe"
  ["address"]=>
  array(3) {
    ["street"]=>
    string(11) "123 Main Street"
    ["city"]=>
    string(7) "Anytown"
    ["state"]=>
    string(2) "CA"
  }
}

Debug Object

Similarly, We can debug the object:

class Person {
    private $name;

    public function __construct($name)
    {
        $this->name = $name;
    }

    public function getName()
    {
        return $this->name;
    }
}

$person = new Person('John Doe');
var_dump($person);

This will produce the following output, which includes the class and properties of the object:

Person(1) {
  +name: private string => John Doe
}

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