Is there a way to output variables in PHP using isset()? - php

Question

I am trying to visualise variables in PHP using isset(), when I am not using it, a notice comes out saying that the index is undefined.
I am trying to output variables in the tabled using the aforementioned function, but with it, the tables do not output any values.
[
<?php
// Include config file
require_once "config.php";
// Attempt select query execution
$sql = "SELECT * FROM courses";
if($result = $pdo->query($sql)){
if($result->rowCount() > 0){
echo "<table class='table table-bordered table-striped'>";
echo "<thead>";
echo "<tr>";
echo "<th>#</th>";
echo "<th>Enquiry ID</th>";
echo "<th>Course Name</th>";
echo "<th>Course Level</th>";
echo "<th>Action</th>";
echo "</tr>";
echo "</thead>";
echo "<tbody>";
while($row = $result->fetch()){
echo "<tr>";
echo "<td>" . isset($row\['courseid'\]) . "</td>";
echo "<td>" . isset($row\['enquiryid'\]) . "</td>";
echo "<td>" . isset($row\['coursename'\]) . "</td>";
echo "<td>" . isset($row\['courselevel'\]) . "</td>";
echo "<td>";
echo "<a href='read.php?id=". isset($row\['courseid'\]) ."' title='View Record' data-toggle='tooltip'><span class='glyphicon glyphicon-eye-open'></span></a>";
echo "<a href='update.php?id=". isset($row\['courseid'\]) ."' title='Update Record' data-toggle='tooltip'><span class='glyphicon glyphicon-pencil'></span></a>";
echo "<a href='delete.php?id=". isset($row\['courseid'\]) ."' title='Delete Record' data-toggle='tooltip'><span class='glyphicon glyphicon-trash'></span></a>";
echo "</td>";
echo "</tr>";
}
echo "</tbody>";
echo "</table>";
// Free result set
unset($result);
} else{
echo "<p class='lead'><em>No records were found.</em></p>";
}
} else{
echo "ERROR: Could not able to execute $sql. " . $mysqli->error;
}
// Close connection
unset($pdo);
?>
]1
I expect the output of the values included in the database tables, but the fields still continue blank.

Answer 1

isset() returns true or false. You can't echo it out directly. You need a conditional that uses isset() to check a variable and display it when true.
On the assumption you're running PHP 7, you can use the null coalescing operator. This acts as a shorthand for a ternary that either results in the variable or a blank string depending on whether the variable is set:
echo "<td>" . $row['courseid'] ?? '' . "</td>";
Documentation: https://php.net/manual/en/migration70.new-features.php#migration70.new-features.null-coalesce-op
This is the equivalent of:
echo "<td>" . isset($row['courseid']) ? $row['courseid'] : '' . "</td>";
If you were forced to use that ternary method however, I'd probably wrap it in a function for convenience.

Answer 2

This isset() Function Returns True/False, So you can not echo out the value directly.
So it's better to use single line condition with isset()
Like i've written below
echo "<td>" . isset($row['courseid']) ? $row['courseid'] : 'Not Set' . "</td>";

Answer 3

I rewrote your while loop as an example:
while($row = $result->fetch()){
echo "<tr>";
if (isset($row['courseid'])){
echo "<td>" . $row['courseid']) . "</td>";
} else {
echo "<td>" . 'NOT SET' . "</td>";
}
if (isset($row['enquiryid'])){
echo "<td>" . $row['enquiryid'] . "</td>";
} else {
echo "<td>" . 'NOT SET' . "</td>";
}
if (isset($row['coursename'])){
echo "<td>" . $row['coursename']. "</td>";
} else {
echo "<td>" . 'NOT SET' . "</td>";
}
if (isset($row['courselevel'])){
echo "<td>" . $row['courselevel']) . "</td>";
} else {
echo "<td>" . 'NOT SET' . "</td>";
}
echo "<td>";
echo "<a href='read.php?id=". $row['courseid'] ."' title='View Record' data-toggle='tooltip'><span class='glyphicon glyphicon-eye-open'></span></a>";
echo "<a href='update.php?id=". $row['courseid'] ."' title='Update Record' data-toggle='tooltip'><span class='glyphicon glyphicon-pencil'></span></a>";
echo "<a href='delete.php?id=". $row\'courseid'] ."' title='Delete Record' data-toggle='tooltip'><span class='glyphicon glyphicon-trash'></span></a>";
echo "</td>";
echo "</tr>";
}
Hope that helps