mysql functions concept

Question

I am new to MySQL and PHP. One thing I'm unable to understand that when we check a given condition in if/else statement. Is the opposite of that condition runs automatically ?

I mean:

<?php
    $link = mysqli_connect('localhost', 'root', 'password');
    if (!$link)
    {
    $output = 'Unable to connect to the database server.';
    include 'output.html.php';
    exit();
    }
?>

Here mysqli_connect is a function and to connect we have to run the function. So the misconception here is that how it is connecting to the server. Since i havn't run the mysqli_function separately. I mean there should be a separate line for that.

OR the opposite of a given condition runs automatically ?

Answer 1

I have declared mysqli_connect in a variable.

No, you haven't.

You have called mysqli_connect and assigned its return value to a variable.

The manual says:

Returns an object which represents the connection to a MySQL Server.

If the connection fails, that that will be a falsey value (which the if statement checks, so it will only do some things if the connection was successful).