What are the advantages and disadvantages of directly embedding variables in strings versus concatenation in PHP?

When working with strings in PHP, there are two common ways to include variables within them: directly embedding variables using double quotes or concatenating variables with the string using the dot (.) operator. Directly embedding variables in strings can make the code cleaner and easier to read, as you don't need to break out of the string to concatenate variables. However, this method can sometimes be less efficient compared to concatenation, especially when dealing with complex expressions or multiple variables within the string. Concatenation, on the other hand, offers more control and flexibility when manipulating strings and variables but can make the code harder to read and maintain. To embed variables directly in strings in PHP, you can use double quotes and wrap the variable in curly braces like so:

$name = "John";
echo "Hello, {$name}!";
```

To concatenate variables with strings in PHP, you can use the dot (.) operator like so:

```php
$name = "John";
echo "Hello, " . $name . "!";