Why Getting Undefined Variable Error In PHP [duplicate] - php

Question

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"Notice: Undefined variable", "Notice: Undefined index", "Warning: Undefined array key", and "Notice: Undefined offset" using PHP
(29 answers)
Closed 3 years ago.
I am trying to run my PHP code, but I am getting an undefined error for the $name variable. The error will show only when it runs for the first time only, but after the second run, it didn't show any error.
<?php
if($_SERVER['REQUEST_METHOD'] == 'POST'){
$name = $nameerr = "";
if(empty($_POST["name"])){
$nameerr = "This Field is Required";
}
else{
$name = test_run($_POST['name']);
}
}
function test_run($data){
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
?>
<form action="<?php htmlspecialchars($_SERVER['PHP_SELF']) ?>" method="POST">
<label for="name">Name: </label>
<input type="text" name="name" value="<?php echo $name;?>"><span>* <?php echo $nameerr ?></span><br><br>
<input type="submit" value="Submit">
</form>
<h1>Output</h1>
<?php
echo $name."<br><br>";
?>

Answer 1

This is because you are not setting the $name variable initially. You are only setting it when a post request is made. So the first time you fetch your script with a GET request, PHP shows you the notice. The second time ( I presume is after you submit your form which initiates a POST request ) the $name variable is set, thus, you do not receive the notice. To resolve this, you can set your $name variable to an empty string above your first if statement.