What common mistake was made in creating the array in the PHP code?
The common mistake made in creating the array in the PHP code is that the key-value pairs were not separated by the "=>" symbol, which is used to assign values to keys in an array. To fix this issue, each key-value pair in the array should be separated by "=>" to properly assign values to keys.
// Incorrect array creation
$student = array("name" "John", "age" 25, "grade" 85);
// Corrected array creation
$student = array("name" => "John", "age" => 25, "grade" => 85);