What does the error "Undefined index" in PHP indicate and how can it be resolved?

The error "Undefined index" in PHP indicates that you are trying to access an array key that does not exist. This can happen when you are trying to access an element in an array using a key that is not defined. To resolve this issue, you should first check if the key exists in the array using the isset() function before trying to access it. 

if(isset($array['key'])) {
    // Access the array element here
    $value = $array['key'];
} else {
    // Handle the case when the key is undefined
    echo "Key does not exist in the array";
}

Keywords

Undefined index PHP error array key resolution

Related Questions