How does PHP handle variable interpolation within strings, and what are the recommended approaches for ensuring consistent and reliable output?

When using variable interpolation within strings in PHP, it is important to ensure that the variables are properly enclosed within curly braces to avoid any ambiguity or unexpected behavior. This helps in maintaining consistent and reliable output by clearly indicating where the variable starts and ends within the string.

// Example of using variable interpolation with curly braces
$name = "John";
$age = 30;

// Recommended approach for ensuring consistent output
echo "My name is {$name} and I am {$age} years old.";