What is the common syntax error in PHP code that results in a "Parse error"?

A common syntax error in PHP code that results in a "Parse error" is missing or mismatched parentheses, brackets, or curly braces. This error occurs when the code structure is not properly closed or opened, causing the PHP parser to be unable to understand the code. To solve this issue, carefully check the opening and closing parentheses, brackets, or curly braces in your code to ensure they are properly matched.

// Incorrect code with missing closing parenthesis
if ($x > 5 {
    echo "x is greater than 5";
}
```

```php
// Corrected code with matching parentheses
if ($x > 5) {
    echo "x is greater than 5";
}