This PPT contains software Testing Fundamentals

1. Learn Software Testing Testing and Verification

34. Testing TrafficSignal (cont.)

40. 1210554 Egyptian Multiplication 2468 490 4936 4936 245 9872 122 19744 19744 61 631808 631808 1 315904 315904 3 157952 157952 7 78976 78976 15 39488 30 1234 1234 981 Remainder “ Doubled” Multiplier “ Halved” Multiplicand

65. The truecase : produces the precondition {(x >= y && x == x) || (x < y && x == y)} which simplifies to {(x >= y && true) || false} and further simplifies to {x >= y} . Backing over the if condition, we get {(x >= y) && (x >= y)} which simplifies to {x >= y} . max = x; {(x >= y && max == x) || (x < y && max == y)} if (x >= y) { max = x; } else { max = y; } {(x >= y && max == x) || (x < y && max == y)} Conditional Statements (cont.)

66. The falsecase : produces the precondition {(x >= y && y == x) || (x < y && y == y)} which simplifies to {(y == x) || (x < y && true)} and further simplifies to {y >= x} . Backing over the negative of the if condition, we get {(y >= x) && (x < y)} which simplifies to {x < y} . max = y; {(x >= y && max == x) || (x < y && max == y)} if (x >= y) { max = x; } else { max = y; } {(x >= y && max == x) || (x < y && max == y)} Conditional Statements (cont.)

67. if (x >= y) { max = x; } else { max = y; } {(x >= y && max == x) || (x < y && max == y)} Combining the results of each pass, we get: {(x >= y) || (x < y)} Since this is always true, it means that the code segment produces the postcondition for all values of x and y . We write the precondition as simply true . Conditional Statements (cont.)