Cookie - 注意：未定义[重复]

Question

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• “Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP 28 answers

I have following code a unfortunately it doesn't work. I get notice Undefined index: imagerotate. I can't solve this problem. Can someone help me please? Thanks.

 <?php
$imgArray = array("header_1000x150_basnenaprani_3_o.png", "header_1000x150_basnenaprani_1_m.png", "header_1000x150_basnenaprani_1-zlatá.png");
// Path to where your images are stored
$hostDir = "http://myweb.com/wp-content/uploads/2015/10/"; // Don't forget that ending '/'

$imgArraySize = count($imgArray); // Store the size of the array (starts at 1)
$imgToShow = 0; // We'll default to always show the first image.

// Check to see if the cookie has already been created.
if ($_COOKIE['imagerotate'] != "") {
  // The cookie existed
  $imgToShow = $_COOKIE['imagerotate'];
  if($imgToShow + 1 >= $imgArraySize) {
    // The image we were supposed to show next would have been out of bounds in the array.
    $imgToShow = 0;  // We'll show the first image
  }
  else  // The image to be shown is not out of bounds.
    $imgToShow++;  // Increment the image counter
}

// Write the new cookie with the new image we are showing
setcookie ("imagerotate", $imgToShow, time()+5);

//Print the image from the directory.
echo "<img src=\"".$hostDir.$imgArray[$imgToShow]."\" alt=\"An Image\" />";

?>

</div>

Answer 1

try this: use "isset" on if statement (tested on phptester.net):

<?php
  $imgArray = array("header_1000x150_basnenaprani_3_o.png","header_1000x150_basnenaprani_1_m.png", "header_1000x150_basnenaprani_1-zlatá.png");
  // Path to where your images are stored
  $hostDir = "http://myweb.com/wp-content/uploads/2015/10/"; // Don't forget that ending '/'

  $imgArraySize = count($imgArray); // Store the size of the array (starts at 1)
  $imgToShow = 0; // We'll default to always show the first image.

  // Check to see if the cookie has already been created.
  if (isset($_COOKIE['imagerotate']) != "") {
   // The cookie existed
    $imgToShow = $_COOKIE['imagerotate'];
    if($imgToShow + 1 >= $imgArraySize) {
    // The image we were supposed to show next would have been out of bounds in the array.
    $imgToShow = 0;  // We'll show the first image
  }
  else  // The image to be shown is not out of bounds.
    $imgToShow++;  // Increment the image counter
  }

 // Write the new cookie with the new image we are showing
 setcookie ("imagerotate", $imgToShow, time()+5);

 //Print the image from the directory.
 echo '<img src="'.$hostDir.$imgArray[$imgToShow].'" alt="An Image" />';

Also, change this line:

echo "<img src=\"".$hostDir.$imgArray[$imgToShow]."\" alt=\"An Image\" />";

to this:

echo '<img src="'.$hostDir.$imgArray[$imgToShow].'" alt="An Image" />';