phpstan_sample.php

<?php

require_once 'vendor/autoload.php';

echo $nodefined;               // Variable $nodefined might not be defined.
$tmp1 = new NoExist();         // Instantiated class NoExist not found.
$tmp2 = noFunction();          // Function noFunction not found

class Hoge {
  public function someMethod(int $someArg): string {
    return 1;                  // Method Hoge::someMethod() should return string but returns int.
    // return 1                // Syntax error, unexpected '}', expecting ';' on line 12
  }

  private function privateMethod() {}

  public function noTypeHint($arg) {
    // Method Hoge::noTypeHint() has parameter $arg with no typehint specified.
    return true;               // Method Hoge::noTypeHint() has no return typehint specified.
  }

  /**
   * @param Hoge $var
   **/
  public function phpdoc1(): void {} // PHPDoc tag @param references unknown parameter: $var

  /**
   * @param Hoge[] $hoges
   **/
  public function phpdoc2(array $hoges): void {
    echo $hoges[0];                  // Parameter #1 (Hoge) of echo cannot be converted to string.
    echo $hoges[0]->methodMissing(); // Call to an undefined method Hoge::methodMissing().
  }

  // Method Hoge::phpdoc3() has parameter $hoges with no value type specified in iterable type array.
  public function phpdoc3(array $hoges): void {}
}

$hoge = new Hoge();
echo $hoge->fuga;              // Access to an undefined property Hoge::$fuga
echo $hoge->hello();           // Call to an undefined method Hoge::hello().
echo $hoge->someMethod();      // Method Hoge::someMethod() invoked with 0 parameters, 1 required.
echo $hoge->someMethod('123'); // Parameter #1 $someArg of method Hoge::someMethod() expects int, string given.
echo $hoge->privateMethod();   // Call to private method privateMethod() of class Hoge.
echo in_array([], "");         // Parameter #2 $haystack of function in_array expects array, string given

if (false) {
  // dead code                 // If condition is always false.
}
$var = new stdClass();
if ($var instanceof Hoge) {}   // Instanceof between stdClass and Hoge will always evaluate to false.

https://phpstan.org/r/0082178d-cc69-4376-9dc0-9c0b24845113