为什么我的程序没有显示用户名？

Question

I am a beginner at PHP and I don't understanding why the code below isn't displaying the user name, as there are no error messages. I have double checked my work and I still can't find an error.

$sql = "SELECT * FROM users";
$result = query($sql);

confirm($result);

$row = fetch_array($result);

echo $row['username'];

?>

This is the db.php file I have created:

<?php 
$con = mysqli_connect('localhost','root','','login_db');

function escape($string) {
    global $con; 

    return mysqli_real_escape_string($con, $string);
}


function query($query) {

    global $con;

    return mysqli_query($con,$query);
}


function fetch_array($result){
    global $con;   

    mysqli_fetch_array($result);
}

function confirm($result) {
    global $con;

    if(!$result) {

        die("Query Failed" . mysqli_error($con)); 
    }

}
?>

Answer 1

You have created the function fetch_array in your db.php file, but don't have a return statement, so it doesn't actually return the array.

Change it to this, to include the return statement.

function fetch_array($result){
    global $con;   

    return mysqli_fetch_array($result);
}