How can developers differentiate between using a period (.) and a comma (,) in PHP code?

In PHP, a period (.) is used for concatenating strings, while a comma (,) is used for separating arguments in a function call or array declaration. To differentiate between the two, developers should be mindful of the context in which they are using these symbols. If you are trying to concatenate strings, use a period. If you are separating arguments or elements, use a comma.

// Example of concatenating strings using a period
$string1 = "Hello";
$string2 = "World";
$combinedString = $string1 . " " . $string2;
echo $combinedString;

// Example of separating arguments using a comma
function exampleFunction($arg1, $arg2) {
  echo $arg1 . " " . $arg2;
}

exampleFunction("Hello", "World");