Undefined variable error php variable search engine

Question

I've basically created a search engine for my website and it seems to work and give results.

However i get this error message:

Notice: Undefined variable: i on line 39

How can I solve this error?

Here is the line in question:

foreach ($terms as $each){
    $i++;

The i++ bit is giving the error.

Here is the code in question:

    <?php include "storescripts/connect_to_mysql.php"; ?>
<?php

$k = $_GET['k'];
$terms = explode(" ", $k);
$query = "SELECT * FROM products WHERE ";


foreach ($terms as $each){
    $i++;

    if ($i == 1)
     $query .= "details LIKE '%$each%' ";
         else
            $query .= "OR details LIKE '%$each%' ";



}

 $query = mysqli_query($link, $query);
 $numrows = mysqli_num_rows ($query);

 if ($numrows > 0) {

     while($row = mysqli_fetch_assoc($query)){ 
             $id = $row["id"];
             $product_name = $row["product_name"];
             $price = $row["price"];
             $details = $row["details"];

     echo "<a href='http://localhost/web/product.php?id=$id'>$product_name</a><br />
<br />
$details<br /><br />
";
     }

 }
     else 
        echo "No results found for \"<b>$k</b>\"";

?>

Answer 1

Simply initialize $i before you use it :-)

$i = 0;
foreach ($terms as $each){
  $i++;
  // ...
}

But be intentional about the use of 0 vs. 1 as your initial value and where else you use that in the code.