echo
can be called with or without parentheses, but it is best practice to leave parentheses off the call because using parentheses
with multiple arguments will result in a parse error.
Noncompliant code example
echo("Hello"); // Noncompliant, but it works
echo("Hello", "World"); // Noncompliant. Parse error
Compliant solution
echo "Hello";
echo "Hello","World!";