Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

 
 class Bar {}
 
-echo '\App\Foo\Bar' . PHP_EOL;
-echo 'App\Foo\Bar' . PHP_EOL;
+echo \App\Foo\Bar::class . PHP_EOL;
+echo \App\Foo\Bar::class . PHP_EOL;
 
-$database_data = 'App\Foo\Bar';
-var_dump('\App\Foo\Bar' == 'App\Foo\Bar');
+$database_data = \App\Foo\Bar::class;
+var_dump(\App\Foo\Bar::class == \App\Foo\Bar::class);
 
-if ($database_data == '\App\Foo\Bar' || $database_data == 'App\Foo\Bar') {
+if ($database_data == \App\Foo\Bar::class || $database_data == \App\Foo\Bar::class) {
   echo 'Matches' . PHP_EOL;
 }

PHP snippet to change

<?php

namespace App\Foo;

class Bar {}

echo '\App\Foo\Bar' . PHP_EOL;
echo 'App\Foo\Bar' . PHP_EOL;

$database_data = 'App\Foo\Bar';
var_dump('\App\Foo\Bar' == 'App\Foo\Bar');

if ($database_data == '\App\Foo\Bar' || $database_data == 'App\Foo\Bar') {
  echo 'Matches' . PHP_EOL;
}

Applied Rules:

StringClassNameToClassConstantRector

Not a change you expect?

Create an issue on GitHub
...or to speed up fix – add a test fixture

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    // B. or few rules
    ->withRules([
                \Rector\Php55\Rector\String_\StringClassNameToClassConstantRector::class
    ])
    // demonstrate specific PHP version
    ->withPhpVersion(PhpVersion::PHP_84);

Rector version: b855ff - released at 2026-01-22 19:37