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Given the following pseudo code for a program to solve quadratic equations:
program Quadratic Formula
integer: a, b, c, d
floating point: r1, r2
READ (a)
READ (b)
READ (c)
d := (b * b) - (4 * a * c)
IF d < 0 THEN
PRINT ("Imaginary Roots")
ELSE
r1 := (-b + sqrt(d)) / (2 * a)
r2 := (-b - sqrt(d)) / (2 * a)
PRINT ("first root is: " r1)
PRINT ("second root is: " r2)
ENDIF
END program Quadratic_Formula
Which of the following checklist items is MOST likely to indicate a problem in this program?
Analysis:
The given pseudo code for solving quadratic equations includes operations that involve division. One of the critical issues in such operations is ensuring that the divisor is not zero, which would result in a division by zero error.
Checklist Item:
D . Are divisors tested for zero or noise?:
This checklist item addresses the potential problem of dividing by zero. In the pseudo code, the variable a is used as a divisor in the formula (-b sqrt(d)) / (2 * a). If a is zero, this will result in a division by zero error. Therefore, it is crucial to test whether a is zero before performing the division.
Explanation of Incorrect Options:
A . Does the code avoid comparing floating point numbers for equality?:
This is important but not directly relevant to the given pseudo code's primary issue.
B . Are all variables properly defined with meaningful, consistent and clear names?:
This is good practice but does not address the critical issue of division by zero.
C . Are there any redundant or unused variables?:
Identifying unused variables is helpful for code clarity but does not address the primary functional issue in the pseudo code.
The ISTQB CTAL-TTA syllabus and standard code review practices emphasize the importance of ensuring safe arithmetic operations, particularly avoiding division by zero.
Sources:
ISTQB-CTAL-TTA Syllabus
General knowledge on code review and arithmetic operations.