Variables, constants, operators and assignment

Overview

Variables, constants and assignment, = against ==, input, MOD, DIV and exponent operators with worked results, comparison operators and Boolean conditions.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What is a variable in a program?

   Model answer

   A variable is a named location in memory that stores a value. The value can change while the program is running.

2. 2

   What is a constant?

   Model answer

   A constant is a named value that stays the same for the whole time a program runs. The program cannot change the value once it is set.

3. 3

   Which keyword declares a constant in OCR Exam Reference Language?

   Model answer

   The keyword const declares a constant. The line const maxPlayers = 4 fixes the player limit at 4.

4. 4

   When should a value be stored as a constant rather than as a variable?

   Model answer

   A constant suits a value that must not change while the program runs, such as the number of days in a week. A variable suits a value that changes, such as a score.

5. 5

   What does assignment mean in programming?

   Model answer

   Assignment stores a value in a variable. The value on the right of the = sign is placed in the variable named on the left.

6. 6

   What is output by x = 4, then x = x + 3, then x = x * 2, then x = x - 5, then print(x)?

   Model answer

   The code outputs 9. The value of x goes from 4 to 7, then to 14, then to 9.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.