In PHP, what are some common mistakes that lead to unexpected syntax errors when working with arrays?

Common mistakes that lead to unexpected syntax errors when working with arrays in PHP include missing commas between array elements, using incorrect array syntax, and forgetting to close array brackets. To solve these issues, double-check your array syntax, ensure that commas are correctly placed between elements, and make sure that array brackets are properly closed. Example:

// Incorrect array declaration with missing comma
$array = [1 2, 3];

// Corrected array declaration with commas between elements
$array = [1, 2, 3];