软件测试作业1
曲星明 3014218129
public int findLast (int[] x, int y) {
//Effects: If x==null throw
NullPointerException
// else return the index of the last element
// in x that equals y.
// If no such element exists, return -1 for (int i=x.length-1; i > 0; i--)
{
if (x[i] == y)
{
return i;
}
}
return -1;
}
// test: x=[2, 3, 5]; y = 2
// Expected = 0
Fault: i>=0
Error: i is 1, not 0, on the last iteration
Actual：-1
Failure: return -1 而不是0
if possible, identify a test case that does not execute the fault. (Reachability)
x=NULL;
If possible, identify a test case that executes the fault, but does not result in an error state.
test: x=[3,2,5]; y=2
If possible identify a test case that results in an error, but not a failure.
test: x=[2,3,5]; y=20
public static int lastZero (int[] x) {
//Effects: if x==null throw
NullPointerException
// else return the index of the LAST 0 in x.
// Return -1 if 0 does not occur in x for (int i = 0; i < x.length; i++)
{
if (x[i] == 0)
{
return i;
}
} return -1;
}
// test: x=[0, 1, 0]
// Expected = 2
Fault:遇到第一个0就return而不是最后一个才return
if possible, identify a test case that does not execute the fault. (Reachability)
x=NULL;
If possible, identify a test case that executes the fault, but does not result in an error state.
test: x=[3,2,9];
If possible identify a test case that results in an error, but not a failure.
test: x=[0,2,9];