<?php
$mysqli=new mysqli("localhost","asasdad","","world");
print_r($mysqli);
if ($mysqli->connect_errno) {
   echo "Failed to connect to Mysql.Error".$mysqli->connect_error;
   exit;
}
#connection is ok
echo "successfully connected to mysql";
$mysqli->set_charset('utf8');

[Running] php "f:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php"
PHP Fatal error:  Uncaught mysqli_sql_exception: Access denied for user 'asasdad'@'localhost' (using password: NO) in F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php:3
Stack trace:
#0 F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php(3): mysqli->__construct('localhost', 'asasdad', Object(SensitiveParameterValue), 'world')
#1 {main}
  thrown in F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php on line 3
Fatal error: Uncaught mysqli_sql_exception: Access denied for user 'asasdad'@'localhost' (using password: NO) in F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php:3
Stack trace:
#0 F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php(3): mysqli->__construct('localhost', 'asasdad', Object(SensitiveParameterValue), 'world')
#1 {main}
  thrown in F:\xampp\htdocs\7learn.php\php-mysql-drivers\mysqli\connection.php on line 3
[Done] exited with code=255 in 0.159 seconds