Final answer:
Statement coverage measures whether each line of code has been executed, while branch coverage ensures that all possible branches in the control flow of a program have been taken during testing. Statement coverage does not necessarily imply branch coverage because you can achieve 100% statement coverage without testing all possible branches of conditional structures.
Step-by-step explanation:
Statement coverage and branch coverage are both methods of testing in software engineering, specifically in the field of software testing. Statement coverage is a metric that defines the percentage of executable lines of code that have been tested by a set of test cases. Conversely, branch coverage, also known as decision coverage, measures the testing of the control structures such as loops and conditional statements within the code.
Statement coverage does not imply branch coverage. Although statement coverage aims to execute every line of code at least once, it doesn't ensure that all possible branches (true/false) of each control structure have been exercised. In contrast, branch coverage requires that each possible path through a given part of code (such as both the true and false paths through an if statement) is taken by the test cases.
To illustrate, consider an 'if' statement with a single line of code inside the 'if' block and another following after the block. If the condition evaluates to true during the test cases, statement coverage would be satisfied since all lines of code have been executed. However, branch coverage would not be satisfied because the case where the condition is false (i.e., the 'else' path) has not been tested.