var_dump - PHP code example

Learn the php Function Var_Dump

The php function var_dump displays structured information about one or more expressions that includes its type and value. Arrays and objects are explored recursively with values indented to show structure. Unlike print_r, var_dump displays structure information as well as human-readable data.

It is vital to learn the php function var_dump as it helps developers to debug their code effectively. Debugging is as important as coding in the field of software development. There might be a situation when a developer needs to verify information about a variable, for instance if a function returns an array it is best to check the return type and contents of the returned value. While a developer can echo the entire contents, var_dump is a great tool for this purpose and it also checks the datatype.

Learn to use the php var_dump function in your code from top-rated online trainers at Simplilearn. The var_dump function is a useful debugging tool in PHP and will help you save time and effort by providing detailed output of variables and their values.

This function is similar to the print_r() function but it provides a lot more information including the value of each element in the array. In addition, this function allows you to print the value of the variable using a hex color and a custom format. Moreover, it is also possible to print the number of elements in an array. If you would like to get more in-depth knowledge about the php function var_dump, then you can enroll for Simplilearn’s Full Stack Web Development Course.

var_dump example

// Simulate a change in the code base         $encodedEnvelope['body'] = str_replace('DummyMessage', 'OupsyMessage', $encodedEnvelope['body']);

        $envelope = $serializer->decode($encodedEnvelope);

        $lastMessageDecodingFailedStamp = $envelope->last(MessageDecodingFailedStamp::class);
        $this->assertInstanceOf(MessageDecodingFailedStamp::class, $lastMessageDecodingFailedStamp);
        $message = $envelope->getMessage();
        // The class does not exist, so we cannot use anything else. The only         // purpose of this feature is to aim debugging (so dumping value)         ob_start();
        var_dump($message);
        $content = ob_get_clean();
        // remove object ID         $content = preg_replace('/#\d+/', '', $content);
        $expected = <<<EOT object(__PHP_Incomplete_Class) (2) { ["__PHP_Incomplete_Class_Name"]=> string(55) "Symfony\Component\Messenger\Tests\Fixtures\OupsyMessage" ["message":"Symfony\Component\Messenger\Tests\Fixtures\OupsyMessage":private]=> string(5) "Hello" }

while (!file_exists($vendor.'/vendor')) {
    $vendor = \dirname($vendor);
}
require $vendor.'/vendor/autoload.php';

Debug::enable();
ini_set('display_errors', 0);

$eHandler = set_error_handler('var_dump');
$xHandler = set_exception_handler('var_dump');

var_dump([
    $eHandler[0] === $xHandler[0] ? 'Error and exception handlers do match' : 'Error and exception handlers are different',
]);

$eHandler[0]->setExceptionHandler('print_r');

if (true) {
    class Broken implements \JsonSerializable
    {
    }
}

        return $container->services['bar'] = new \Symfony\Component\DependencyInjection\Tests\Dumper\LazyClosureConsumer(#[\Closure(name: 'foo', class: 'Symfony\\Component\\DependencyInjection\\Tests\\Compiler\\Foo')] fn () => ($container->services['foo'] ??= new \Symfony\Component\DependencyInjection\Tests\Compiler\Foo()), ($container->services['baz'] ?? self::getBazService($container)), ($container->services['foo'] ??= new \Symfony\Component\DependencyInjection\Tests\Compiler\Foo())->cloneFoo(...), ($container->services['my_callable'] ??= new \Symfony\Component\DependencyInjection\Tests\Compiler\MyCallable())->__invoke(...));     }

    /** * Gets the public 'baz' shared service. * * @return \Closure */
    protected static function getBazService($container)
    {
        return $container->services['baz'] = \var_dump(...);
    }

    /** * Gets the public 'foo' shared service. * * @return \Symfony\Component\DependencyInjection\Tests\Compiler\Foo */
    protected static function getFooService($container)
    {
        return $container->services['foo'] = new \Symfony\Component\DependencyInjection\Tests\Compiler\Foo();
    }

ob_start();

    if (!$vars) {
        $vars = [];
        foreach ($context as $key => $value) {
            if (!$value instanceof Template && !$value instanceof TemplateWrapper) {
                $vars[$key] = $value;
            }
        }

        var_dump($vars);
    } else {
        var_dump(...$vars);
    }

    return ob_get_clean();
}
}

    public static function describeType($input): string
    {
        switch (\gettype($input)) {
            case 'object':
                return 'object('.\get_class($input).')';
            case 'array':
                return 'array('.\count($input).')';
            default:
                \ob_start();
                \var_dump($input);
                // normalize float vs double                 /** @var string $varDumpContent */
                $varDumpContent = \ob_get_clean();

                return \str_replace('double(', 'float(', \rtrim($varDumpContent));
        }
    }

    /** * Parses an array of header lines into an associative array of headers. * * @param iterable $lines Header lines array of strings in the following * format: "Name: Value" */

EOTXT;
        ob_start();
        var_dump($clone);
        $this->assertStringMatchesFormat(str_replace('"1"', '1', $expected), ob_get_clean());
    }

    public function testCaster()
    {
        $cloner = new VarCloner([
            '*' => fn ($obj, $array) => ['foo' => 123],
            __CLASS__ => function D$obj, $array) {
                ++$array['foo'];

                return $array;
            },

    function _handleError($err)
    {
        if ($err['level'] == 'exception') {
            $message = $err['message'];
            if (isset($_SERVER['REQUEST_URI'])) {
                echo '<br />';
            } else {
                echo "\n";
            }
            var_dump($err['context']);
            die($message);
        }
    }

    /** * Set up a PEAR::Log object for all error stacks that don't have one * @param Log $log */
    public static function setDefaultLogger(&$log)
    {
        if (is_object($log) && method_exists($log, 'log') ) {

/** * @return void */
    public function onKernelException(ExceptionEvent $event)
    {
        if (null === $this->controller) {
            return;
        }

        $throwable = $event->getThrowable();

        if ($exceptionHandler = set_exception_handler(var_dump(...))) {
            restore_exception_handler();
            if (\is_array($exceptionHandler) && $exceptionHandler[0] instanceof ErrorHandler) {
                $throwable = $exceptionHandler[0]->enhanceError($event->getThrowable());
            }
        }

        $request = $this->duplicateRequest($throwable, $event->getRequest());

        try {
            $response = $event->getKernel()->handle($request, HttpKernelInterface::SUB_REQUEST, false);
        } catch (\Exception $e) {

trigger_error('unsilenced bar deprecation', E_USER_DEPRECATED);
}
}

@trigger_error('root deprecation', E_USER_DEPRECATED);

$foo = new FooTestCase();
$foo->testLegacyFoo();
$foo->testLegacyBar();

register_shutdown_function(function D) use ($filename) {
var_dump(file_get_contents($filename));
});
?> --EXPECTF-- string(234) " Unsilenced deprecation notices (3) 2x: unsilenced foo deprecation 2x in FooTestCase::testLegacyFoo 1x: unsilenced bar deprecation 1x in FooTestCase::testLegacyBar Other deprecation notices (1) 1x: root deprecation "