Types and constants · ⁨타입과 상수⁩

Six data types

• The 2026 guide uses INTEGER, REAL, CHAR, STRING, BOOLEAN and DATE.
• DATE is in this guide. It is not in the IGCSE 0478 syllabus for 2026–2028.
• A paper that uses a date tells you the format, because dates are written differently around the world.

DECLARE Name : STRING
DECLARE Done : BOOLEAN
DECLARE Birth : DATE
Name ← "Ada"
Done ← TRUE
OUTPUT Name
OUTPUT Done

CONSTANT uses =

• A constant is a name for a value that the program does not change.
• The guide writes CONSTANT HourlyRate = 6.50 — with =, not with the arrow.
• Only a literal may stand on the right: a number, or text in quotes.

CONSTANT PassMark = 50
OUTPUT PassMark

Watch out

• Variables are stored with ←. Constants are declared with =.
• The guide's own date example is written 02/01/2005. On the paper, follow the format the question gives you.

Common mistakes

• BOOLEAN values are TRUE and FALSE, in capitals.
• A CHAR is one character in single quotes, such as 'A'. A STRING uses double quotes.

Now you try

• Declare a constant with = and output it.
• Text needs quotes: "Ada", not Ada.