DECLARE
  number1 NUMBER(2);
  number2 NUMBER(2)    := 17;
  text1    VARCHAR2(12) := 'Hello world';
  text2    DATE         := SYSDATE;        -- current date and time
BEGIN
  SELECT street_number
  INTO   number1
  FROM   address
  WHERE  name = 'Smith';
END;

Test PL/SQL syntax highlighting

PL/SQL