CTFL_Syll2018 Exam Dumps : ISTQB Certified Tester Foundation Level (Syllabus 2018)

100% branch coverage means 100% statement coverage, but not vice-versa. Branch coverage is a stronger criterion than statement coverage, as it requires that every possible outcome of each decision point is executed at least once. Statement coverage only requires that every executable statement is executed at least once1 explains this as follows:

Branch Coverage (also known as Decision Coverage) measures which possible branches in flow control structures are followed. Branch Coverage is a testing method, which aims to ensure that each one of the possible branch from each decision point is executed at least once and thereby ensuring that all reachable code is executed.

Statement Coverage measures the number of statements in the source code that are executed during the test. Statement Coverage is a metric, which is used to calculate and measure the number of statements in the source code which have been executed during testing.

B, C, and D are false statements. 100% statement coverage does not mean 100% branch coverage (B), as there may be some branches that are not covered by the test cases. 100% branch coverage does not mean 100% statement coverage and vice-versa ©, as branch coverage implies statement coverage but not the other way around. It is possible to achieve 100% statement coverage (D), but it may not be feasible or cost-effective for some systems.

One of the basic principles of testing is that for a software system, it is not possible under normal conditions to test all input and output combinations because they are too many and too complex to cover within a reasonable time and budget. Therefore, testers have to select a subset of inputs and outputs that are representative and relevant for testing based on criteria such as requirements, risks, priorities, etc. This principle implies that testing cannot prove that a software system is defect-free or has a certain level of quality because there might be some untested inputs or outputs that could reveal defects or failures. Testing can only provide information about the quality and risk level of a software system based on the observed behavior and results under certain conditions and assumptions. You can find more information about the basic principles of testing in A Study Guide to the ISTQB® Foundation Level 2018 Syllabus, Chapter 11.

The statement that component testing tests interfaces between modules and interactions of different parts of a system does not describe component testing. Component testing is the process of testing individual software components that are separately testable, such as modules, programs, objects, classes, etc. Component testing verifies the functionality and quality of the components in isolation from other components. Component testing does not test the interfaces or interactions between components, as this is done in integration testing.

References: Certified Tester Foundation Level Syllabus, Section 5.1.2