How can PHP syntax errors be avoided when concatenating variables with strings in header functions?

When concatenating variables with strings in header functions, it's important to ensure that the variables are properly enclosed within curly braces `{}` to avoid PHP syntax errors. This is necessary because PHP interprets variables within double quotes, but when using them in header functions, the syntax can get confusing. By enclosing the variables in curly braces, you explicitly tell PHP where the variable begins and ends.

// Example of concatenating variables with strings in header functions
$name = "John";
header("Location: /welcome.php?name={$name}");