PHP Notice Undefined: Post contains Notice Undefined index, and Notice Undefined offset reasons and solutions to fix undefined notices.

PHP Notice Undefined variable

Following is reason and solution for PHP Undefined variable notice.

Why PHP generate Undefined variable Notice?

When you try to access variable, which not defined or not available in scope, PHP generate Undefined variable Notice.

Example case:


echo $variableName;

Above example case result output will be NOTICE Undefined variable: variableName on line number 3.

Solutions for PHP Undefined variable Notice?

Following are useful solutions for PHP Undefined variable Notice. You can apply it based on your code process to fix undefined variable Notice.

  • Use PHP isset function.
  • Use PHP isset function with ternary.
  • Use PHP ?? null coalescing operator.
//isset
if (isset($variableName)) {
    echo $variableName;
}

//isset with ternary
echo isset($variableName) ? $variableName : '';

//null coalescing operator
echo ($variableName ?? '');

PHP Notice Undefined index

Following is reason and solution for PHP Undefined index notice.

Why PHP generate Undefined index Notice?

When you try to access index key, which not defined or not exist in array, PHP generate Undefined index Notice. This notice generate when you try to access array with sting key, which not defined in array.

Example case:

$itemList = ['key_one' => 'test', 'key_two' => 'notice'];
echo $itemList['key_three'];

Given example case result output will be NOTICE Undefined index: key_three on line number 4.

Solutions for PHP Undefined index Notice?

Following are useful solutions for PHP Undefined index Notice. You can apply it based on your code process to fix Undefined index Notice.

  • Use PHP isset function.
  • Use PHP isset function with ternary.
  • Use PHP ?? null coalescing operator.
//isset
if (isset($itemList['key_three'])) {
    echo $itemList['key_three'];
}

//isset with ternary
echo isset($itemList['key_three']) ? $itemList['key_three'] : '';

//null coalescing operator
echo ($itemList['key_three'] ?? '');

PHP Notice Undefined offset

Following is reason and solution for PHP Undefined offset notice.

Why PHP generate Undefined offset Notice?

When you try to access array value by offset number, which not defined or not exist in array, PHP generate undefined offset Notice. This notice generate when you try to access array with integer offset, which not defined in array.

Example case:

$itemList = ['test', 'notice'];
echo $itemList[2];

Result output of example case will be NOTICE Undefined offset: 2 on line number 4.

Solutions for PHP Undefined offset Notice?

Following are useful solutions for PHP Undefined offset Notice. You can apply it based on your code process to fix undefined offset Notice.

  • Use PHP isset function.
  • Use PHP isset function with ternary.
  • Use PHP ?? null coalescing operator.
//isset
if (isset($itemList[2])) {
    echo $itemList[2];
}

//isset with ternary
echo isset($itemList[2]) ? $itemList[2] : '';

//null coalescing operator
echo ($itemList[2] ?? '');

Above given are reasons and solutions for PHP Notices variable and array index and offset. You can try solutions based on your code process. If you have other solutions, you can share it here using your comment. It will definitely useful for other users.