ITPEC FE Subject A April 2024 Question 37

Boundary Value Analysis — select test values at the edges of a valid range.

Given condition 25 ≤ x < 50 (integer):

• •Valid range: 25 to 49 (since x is integer and x < 50, max valid = 49)
• •Left boundary = 25 → test 24 (invalid) and 25 (valid)
• •Right boundary = 49 → test 49 (valid) and 50 (invalid)

Test set: 24, 25, 49, 50

Why not others:
- (b) 24, 25, 50, 51 — treats 50 as the boundary, but 50 is already invalid; the real upper boundary is 49
- (c) 25, 26, 49, 50 — 26 is not a boundary-adjacent value
- (d) 25, 26, 50, 51 — 26 is interior; 51 is two steps from the valid range

Key rule: For integers with x < N, the upper boundary of the valid range is N - 1. Apply BVA to the actual valid range boundaries, not to the condition's literal values.

AI-generated — may contain errors