Software testing foundations homework2

Below are two faulty programs. Each includes a test case that results in failure. Answer the following questions (in the next slide) about each program.

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

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

56