Variable CS Thinking Example 2
Follow the full solution, then compare it with the other examples linked below.
Example 2
mediumShow how to swap the values of two variables a and b using a temporary variable. Trace with a = 5, b = 9.
Solution
- 1 Step 1: SET temp = a. Now temp = 5, a = 5, b = 9.
- 2 Step 2: SET a = b. Now temp = 5, a = 9, b = 9.
- 3 Step 3: SET b = temp. Now temp = 5, a = 9, b = 5. Values swapped.
Answer
After swap: a = 9, b = 5. Use a temporary variable to avoid overwriting.
Swapping without a temporary variable would lose one value. The temp variable acts as a holding space — a classic pattern in programming.
About Variable
A named container in a program that stores a value, which can be read, updated, or replaced. Variables have a name (identifier), a value (the data stored), and in many languages a type (what kind of data it holds).
Learn more about Variable →More Variable Examples
Example 1 easy
Trace: SET x = 7. SET y = x + 3. SET x = y * 2. OUTPUT x, y.
Example 3 easyWhat is the output? SET score = 0. SET score = score + 10. SET score = score + 5. OUTPUT score.
Example 4 mediumTrace this swap algorithm: SET A = 3. SET B = 8. SET temp = A. SET A = B. SET B = temp. What are A a