What best practices should be followed when concatenating variables with strings in PHP?

When concatenating variables with strings in PHP, it is best practice to use the "." operator to combine the variables and strings. This helps to improve code readability and maintainability. Additionally, it is recommended to enclose variables in curly braces {} within double quotes to clearly separate them from the surrounding text.

// Example of concatenating variables with strings in PHP
$name = "John";
$age = 25;

// Using the "." operator to concatenate variables with strings
echo "Hello, " . $name . "! You are " . $age . " years old.";

// Using curly braces {} to enclose variables within double quotes
echo "Hello, {$name}! You are {$age} years old.";