Errors that can be caught in php : version PHP 7+
```
first:
$i = 0;
try {
	if ( $i == 0 )
		$link = mysqli_connect("1.1.1.1", "my_user", "my_password", "my_db");
	else
		echo 'Another link.';

} catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "\n";
	$i = 1;
	goto first;
}

// Continue execution
echo 'repair complete!';
```
This error can be caught.
```
Warning: mysqli_connect(): (HY000/2002):
repair complete!
````
BUT ,If it looks like this
```
first:
$i = 0;
try {
	if ( $i == 0 )
		$link = mysql_connect("1.1.1.1", "my_user", "my_password", "my_db");
	else
		echo 'Another link.';

} catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "\n";
	$i = 1;
	goto first;
}

// Continue execution
echo 'repair complete!';
```
This error cannot be caught.
```
Fatal error: Uncaught Error: Call to undefined function mysql_connect() in D:\wamp64\www\test.php:409 Stack trace: #0 {main} thrown in D:\wamp64\www\test.php on line 409
```
So ,I wonder what types of errors can be caught.Then I can do something about it.