Write pseudocode statements for: the declaration of variables

11.1 Programming Basics

Variable Declaration in Pseudocode

Think of a variable as a labelled box 📦 that can hold a value. In pseudocode we first declare the box so the computer knows what kind of value it can store. The general form is: 

DECLARE <variable_name> AS <data_type>

Analogy: Declaring a variable is like putting a name tag on a storage box. The data type tells the box how big it should be and what kind of items it can hold (numbers, words, etc.). Without a name tag, the computer would not know which box to use when you later refer to it.

Common Data Types

Data Type Description Example Declaration
INTEGER Whole numbers (e.g., 0, 7, -12) DECLARE age AS INTEGER
REAL Numbers with a decimal point (e.g., 3.14, -0.001) DECLARE height AS REAL
STRING Sequences of characters (e.g., "Alice", "Hello, world!") DECLARE name AS STRING
BOOLEAN True or False values DECLARE isStudent AS BOOLEAN

Putting It All Together

  1. Choose a clear, descriptive name for your variable.
  2. Select the appropriate data type.
  3. Write the declaration using the DECLARE keyword.
  4. Optionally, initialise the variable: DECLARE counter AS INTEGER = 0.
Exam Tip:
  • Always use the DECLARE keyword when introducing a new variable.
  • Specify the data type; omitting it can lead to errors.
  • Remember that pseudocode is case‑insensitive, but keep your style consistent.
  • Use initialisation only when you know the starting value.
Common Mistakes
  • Declaring a variable without a data type.
  • Using reserved words (e.g., DECLARE, INTEGER) as variable names.
  • Mixing up data types (e.g., assigning a string to an integer variable).
  • Forgetting to initialise variables that will be used in calculations.

Quick Practice

Try declaring the following variables in pseudocode:

  1. A variable score that holds a whole number.
  2. A variable temperature that holds a real number.
  3. A variable studentName that holds a string.
  4. A variable hasPassed that holds a boolean.

Write your answers below and check them against the examples above. Happy coding! 🚀

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