Showing Error in a php function

Question

I have declared a function called test_input in my php script,which working absolutely fine in another scripts.

It shows error

Fatal error: Uncaught Error: Call to undefined function test_input() in C:\xampp\htdocs\submitdata\cwisubmit.php:25 Stack trace: #0 {main} thrown in C:\xampp\htdocs\submitdata\cwisubmit.php on line 25

My php script is:

<?php 
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "test";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
 die("Connection failed: " . $conn->connect_error);
} 
echo "Database Connected SUCCESSFULLY";
if($_SERVER["REQUEST_METHOD"]=="POST") {
 // Variables initialization
 $fname=$lname=$dob=$phone=$email=$postcode=$staddress=$city=$lan=$lcwi=$ptype=$mhtype="";
 // Retrieving the data from the form
 $fname=test_input(mysqli_real_escape_string($conn,$_POST['fname']));
 $lname=test_input(mysqli_real_escape_string($conn,$_POST['lname']));
 $dob=test_input(mysqli_real_escape_string($conn,$_POST['dob']));
 $phone=test_input(mysqli_real_escape_string($conn,$_POST['phone']));
 $email=test_input(mysqli_real_escape_string($conn,$_POST['email']));
 $postcode=test_input(mysqli_real_escape_string($conn,$_POST['postcode']));
 $staddress=test_input(mysqli_real_escape_string($conn,$_POST['staddress']));
 $city=test_input(mysqli_real_escape_string($conn,$_POST['city']));
 $lan=test_input(mysqli_real_escape_string($conn,$_POST['lan']));
 $lcwi=test_input(mysqli_real_escape_string($conn,$_POST['lcwi']));
 $ptype=test_input(mysqli_real_escape_string($conn,$_POST['ptype']));
 $mhtype=test_input(mysqli_real_escape_string($conn,$_POST['mhtype']));
 function test_input($data) {
 $data=trim($data);
 $data=stripslashes($data);
 return $data;
 }
 //sql insert
 $sql="INSERT INTO cwi(fname, lname, dob, phone, email, postcode, staddress, city, lan, lcwi, ptype, mhtype) VALUES('$fname','$lname','$dob','$phone','$email','$postcode','$staddress','$city','$lan','$lcwi','$ptype','$mhtype')";
 if($conn->query($sql)===TRUE){
 echo "<center>RECORDS UPDATED SUCCESSFULLY</center>";
 }else{
 echo "Error: ".$sql."<br>".$conn->error;
 }
}
$conn->close();
?>

Please check this code whether there is error in my code or why its returning this error

Answer 1

PHP functions can be called before defining it because PHP parses the file first and then executes it. But here is the twist.

Functions that are enclosed in a conditional statement(if else) will not be parsed. It will be only available after PHP interprets if

So, You have to move your function outside of IF block like

if(condition){
//your code
}
//Your function
 function test_input($data){
 $data=trim($data);
 $data=stripslashes($data);
 return $data;
 }

Answer 2

define your test_input() function outside of

if($_SERVER["REQUEST_METHOD"]=="POST"){

and your code

 if($_SERVER["REQUEST_METHOD"]=="POST"){ 

seems miss "}"

Answer 3

Changes are made to the code try this. It should work fine.

<?php 
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "test";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
 if ($conn->connect_error) 
 {
 die("Connection failed: " . $conn->connect_error);
 } 
echo "Database Connected SUCCESSFULLY";
 if($_SERVER["REQUEST_METHOD"]=="POST"){
 //Variables initaition
 $fname=$lname=$dob=$phone=$email=$postcode=$staddress=$city=$lan=$lcwi=$ptype=$mhtype="";
 //Retrieving the data from the form
 $fname=test_input(mysqli_real_escape_string($conn,$_POST['fname']));
 $lname=test_input(mysqli_real_escape_string($conn,$_POST['lname']));
 $dob=test_input(mysqli_real_escape_string($conn,$_POST['dob']));
 $phone=test_input(mysqli_real_escape_string($conn,$_POST['phone']));
 $email=test_input(mysqli_real_escape_string($conn,$_POST['email']));
 $postcode=test_input(mysqli_real_escape_string($conn,$_POST['postcode']));
 $staddress=test_input(mysqli_real_escape_string($conn,$_POST['staddress']));
 $city=test_input(mysqli_real_escape_string($conn,$_POST['city']));
 $lan=test_input(mysqli_real_escape_string($conn,$_POST['lan']));
 $lcwi=test_input(mysqli_real_escape_string($conn,$_POST['lcwi']));
 $ptype=test_input(mysqli_real_escape_string($conn,$_POST['ptype']));
 $mhtype=test_input(mysqli_real_escape_string($conn,$_POST['mhtype']));
 //sql insert
 $sql="INSERT INTO cwi(fname, lname, dob, phone, email, postcode, staddress, city, lan, lcwi, ptype, mhtype) VALUES('$fname','$lname','$dob','$phone','$email','$postcode','$staddress','$city','$lan','$lcwi','$ptype','$mhtype')";
 if($conn->query($sql)===TRUE){
 echo "<center>RECORDS UPDATED SUCCESSFULLY</center>";
 }else{
 echo "Error: ".$sql."<br>".$conn->error;
 }
 }
 $conn->close();
 function test_input($data)
 {
 $data=trim($data);
 $data=stripslashes($data);
 return $data;
 }
?>