Page 53 - SOFTWARE TESTING & QUALITY ASSURANCE

Software Testing and Quality Assurance

2. Data Declaration Errors: Data declaration errors occur due to improper declaration of variables
and constants.
Some of the common points to ponder on while checking for data declaration errors are:

(a) Check if the variables are assigned the correct length, type, storage class

A variable that is incorrectly declared as an array instead of a string.

(b) Check if a variable is initialized at the time of declaration, and also analyze if it is properly
initialized and consistent with its type
(c) Check if there are any variables with similar names
(d) Check if there are any variables declared which are never referenced or just referenced once
(should be a constant)
(e) Check if all variables are explicitly declared within a specific module

3. Computation Errors: Computational errors arise due to errors in calculations -- where the
expected results are not obtained due to erroneous calculations.
Some of the questions pertaining to computational errors are:
(a) Check if any calculations use variables which have different data types

Adding integers and floating point numbers

(b) Check if any calculations use variables which have the same data type but vary in size

Adding long integers to short integers

(c) Check if the compiler’s conversion rules for variables of inconsistent type or size
understood and considered while calculating
(d) Check if overflow or underflow in the middle of a numeric calculation possible
(e) Check if it is ever possible for a divisor/modulus to be zero

(f) Check if a variable’s value goes outside its meaningful range
The probability of a result being less than zero percent or greater than 100
percent.

(g) Check if the target variable of an assignment is smaller than the right-hand expression
(h) Check if parentheses are needed for clarification

For expressions containing multiple operators, there is confusion about the
order of evaluation.

(i) Check if for cases of integer arithmetic, the code handles some calculations, particularly
division, which results in loss of precision
4. Comparison Errors: Comparison errors occur during boundary conditions such as ‘less than,
greater than, equal, not equal, and true or false’.
Some of the common points to be analyzed for comparison errors are:
(a) Check if the comparisons are correct

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