Variables, DECLARE and CONSTANT

A variable stores a value

• A variable holds a value you can use and change.
• The arrow ← puts a value into a variable (this is assignment).
• On your keyboard, type <- (less-than, minus) — it means the same as ←.

Age ← 16
OUTPUT Age      // → 16
OUTPUT "Age"    // → Age

DECLARE names the type

• DECLARE states a variable's name and its data type.
• It is good style to declare a variable before you use it.

DECLARE Count : INTEGER
Count ← 0
OUTPUT Count    // → 0

You can change a variable

• Assign again to give a variable a new value.
• The right-hand side is worked out first, then stored.

Total ← 10
Total ← Total + 5
OUTPUT Total    // → 15

A constant does not change

• A constant is a name for a value the program must not change, such as a pass mark or an hourly rate.
• The 2026–2028 syllabus writes CONSTANT HourlyRate ← 6.50 — the arrow, then a literal only.
• If the number changes next year, you edit that one line and every use of the name follows.

CONSTANT PassMark ← 50
OUTPUT PassMark     // → 50

Watch out

• ← (or <-) means store into. It is not the = used to test equality.
• A variable keeps its last value until you assign a new one.
• OUTPUT Age prints the number in the box. OUTPUT "Age" prints the word Age.

Common mistakes

• DECLARE <identifier> : <data type> before you use a variable.
• A constant is CONSTANT <identifier> ← <value>. Assign a variable with ←.

Now you try

• Type <- for the ← arrow.
• Press Run to see the output, then Check answer.