HomeWork2

a）相关定义：

• Software Fault : A static defect in the software
• Software Failure : External, incorrect behavior with respect to the requirements or other description of the expected behavior
• Software Error : An incorrect internal state that is the manifestation of some fault

b）题目描述：

c）相关问题及作答：

n  Identify the fault.

Answer：左边的程序代码for循环不能到达x数组下标为0的位置，产生了数据遗漏；右边程序代码实现的功能是找出x数组中第一个0出现的位置，而不是最后一个0，程序功能和描述不符。

n  If possible, identify a test case that does not execute the fault. (Reachability)

Answer：左边程序：x = null, y=0；右边程序：x = null。

n  If possible, identify a test case that executes the fault, but does not result in an error state.

Answer：左边程序：x = [5,2,0], y=5；右边程序：x = [0]。

n  If possible identify a test case that results in an error, but not a failure.

 Answer：左边程序：x = [5,2,0], y=8；右边程序：x = [5,0,2]。