ISTQB - International Software Testing Qualifications Board White-Box Test Design Questions and Answers

Question 1

A developer has written the following pseudocode. What is the MINIMUM number of test cases required to achieve 100% statement coverage?

READ A
READ B
IF A > B THEN
  PRINT A
ELSE
  PRINT B
ENDIF

Accepted Answer

2

Answer

1

Answer

3

Answer

4

Question 2

Which of the following BEST defines Decision Coverage?

Accepted Answer

It ensures that every possible outcome (TRUE and FALSE) of each decision point in the code has been exercised at least once.

Answer

It ensures that every executable statement in the code has been tested at least once.

Answer

It measures the percentage of independent paths through the code that have been exercised.

Answer

It verifies that every function call within the code has been executed.

Question 3

Which of the following statements about the relationship between statement coverage and decision coverage is correct?

Accepted Answer

Achieving 100% decision coverage guarantees 100% statement coverage.

Answer

Achieving 100% statement coverage guarantees 100% decision coverage.

Answer

Statement coverage and decision coverage are independent of each other.

Answer

Achieving 50% decision coverage guarantees 100% statement coverage.

Question 4

What is the primary goal of Modified Condition/Decision Coverage (MC/DC), a technique often required for safety-critical systems?

Accepted Answer

To show that each condition within a decision can independently affect the outcome of that decision.

Answer

To test every possible combination of conditions within a decision.

Answer

To execute every statement in the software at least once.

Answer

To ensure that every function in the code has been called with every possible parameter value.

Question 5

A tester is using white-box test design techniques. In which of the following areas are these techniques MOST effective for finding defects?

Accepted Answer

Uncovering logic errors and incorrect assumptions in the code's control flow.

Answer

Identifying missing requirements or specification ambiguities.

Answer

Finding defects in the graphical user interface (GUI) layout.

Answer

Validating that the software meets the end-user's business needs.

Question 6

Consider a simple function with a single `IF-THEN-ELSE` statement followed by another independent `IF-THEN-ELSE` statement. How many distinct paths exist through this function that need to be tested for 100% path coverage?

Accepted Answer

4

Answer

1

Answer

2

Answer

8