• Desk Checking:
  • Verifying that a program satisfies specifications by carefully reading the code
• Testing:
  • Verifying that a program satisfies specifications by executing the code
• Debugging:
  • Locating and repairing logic errors

• Conditions Involving Equality:
  • Check for the use of = instead of ==
  • Check for the use of == instead of .equals() with reference types
  • Check for the use of == with floating point numbers
• Conditions Involving Inequality:
  • Check for directionality mistakes
  • Check for weak inequalities in the place of strict inequalities

• The Sets Involved:
  • A discrete set of elements
  • A continuous range/interval of elements
• The Condition(s):
  • Single
  • Compound
  • Nested

• Possible Errors:
  • An error involving one or more elements of the set
  • An error that involves non-elements
• Test Cases to Include:
  • Each member of the set
  • A value smaller than the smallest member
  • A value larger than the largest member
  • A value between two members

An Example:

  if (seatLocationCode == 100) 
  {
    // ...
  } 
  else if (seatLocationCode == 200) 
  {
    // ...
  } 
  else if (seatLocationCode == 300) 
  {
    // ...
  } 
  else 
  {
    // ...
  }
  

Test cases: 50 100 150 200 300 1000

• Possible Errors:
  • An error involving one or more elements of the set
  • An error that involves a boundary of the set (whether the interval is open or closed)
  • An error that involves non-elements
• Test Cases to Include:
  • Several elements in the interval
  • A value smaller than the lower bound
  • A value larger than the upper bound
  • The lower bound
  • The upper bound

An Example:

  if ((income > 0.0) && (income < 20000.0))
  {
     // ...
  }
  else 
  {
     // ...
  }
  

Test cases: -1.0 0.0 10000.0 20000.0 20001.0

• Possible Errors:
  • All of the errors above, but now in various combinations
• Test Cases to Include:
  • All combinations (if possible)

An Example of a Compound Condition:

  if ((height >= 62) && (sex == 'M'))
  {
    // ...
  }
  

Test cases:
70, 'M'
70, 'F'
62, 'M'
62, 'F'
50, 'M'
50, 'F'

An Example of Nested Conditions:

if (height >= 62) 
{
  if (sex == 'M') 
  {
    // ...
  } 
  else
  {
    // ...
  }
} 
else 
{
  if (sex == 'M') 
  {
    // ...
  }
  else 
  {
    // ...
  }
}
  

Test cases:
70, 'M'
70, 'F'
62, 'M'
62, 'F'
50, 'M'
50, 'F'

• The Basics:
  • Include print() calls before, inside, and after the conditional statements
  • Include print() calls that check for "accidental assignments" (i.e., use of the = operator instead of the == operator)
• A Warning:
  • You may need to reorganize your code (e.g., use intermediate variables) in order to print some values

javaexamples/basics/DebuggingConditionals.java (Fragment: 0)

        // For debugging
        JMUConsole.printf("Before: height(%d) sex(%c)", height, sex);
        JMUConsole.printf("        (height >= 62)  %s)",(height>=62));
        JMUConsole.printf("        (sex == 'M')    %s)",(sex=='M'));

        if ((height >= 62) && (sex == 'M')) 
        {
            // For debugging
            JMUConsole.printf("In if-block: height(%d) sex(%c)", height, sex);

            // ...
        }
        else 
        {
            // For debugging
            JMUConsole.printf("In else-block: height(%d) sex(%c)", height, sex);

            // ...
        }
        // For debugging
        JMUConsole.printf("After: height(%d) sex(%c)", height, sex);