Software testing foundations homework2,

Software testing foundations homework2,
Homework 2

Below are two faulty programs. Each except des 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

Questions

Identify the fault. If possible, identify a test case that does not execute Fault. (Reachability) If possible, identify a test case that executes the fault, butdoes not result in an error state. If possible identify a test case that results in an error, butnot a failure. Due Date: 23:59:59 March 15. Please send your answer to tjuscsst@qq.com and post itto your blog.

Solution: 1.1) the condition in the for loop should be I> = 0, otherwise return-1 directly to 0. 2) test: x = []; y = 23) test: x = [2, 3, 5]; y = 54) test: x = [2, 3, 5]; y = 92.1) The for loop should be open from the last bit of the array; otherwise, the first 02 is found) test: x = [] 3) test: x = [1, 1, 1] 4) test: x = [0, 1, 1]