How can the error "syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE)" be resolved in PHP code?

The error "syntax error, unexpected '' (T_ENCAPSED_AND_WHITESPACE)" occurs when there is a syntax issue with string concatenation in PHP code. This error often happens when there is a missing or misplaced quotation mark within a string. To resolve this error, make sure to properly enclose your variables or expressions within double quotes when concatenating them with strings.

// Incorrect code causing the error
$name = "John";
echo "Hello, $name"!";
```

```php
// Corrected code with proper string concatenation
$name = "John";
echo "Hello, $name!";