Example 1
The following Java example contains a function to compute an average
but does not validate that the input value used as the denominator is not
zero. This will create an exception for attempting to divide by zero. If
this error is not handled by Java exception handling, unexpected results can
occur.
(Bad Code)
Example
Language: Java
public int computeAverageResponseTime (int totalTime, int
numRequests) {
return totalTime / numRequests;
}
By validating the input value used as the denominator the following
code will ensure that a divide by zero error will not cause unexpected
results. The following Java code example will validate the input value,
output an error message, and throw an exception.
public int computeAverageResponseTime (int totalTime, int
numRequests) throws ArithmeticException {
if (numRequests == 0) {
System.out.println("Division by zero attempted!");
throw ArithmeticException;
}
return totalTime / numRequests;
}
Example 2
The following C/C++ example contains a function that divides two
numeric values without verifying that the input value used as the
denominator is not zero. This will create an error for attempting to divide
by zero, if this error is not caught by the error handling capabilities of
the language, unexpected results can occur.
(Bad Code)
Example Languages: C and C++
double divide(double x, double y){
}
By validating the input value used as the denominator the following
code will ensure that a divide by zero error will not cause unexpected
results. If the method is called and a zero is passed as the second
argument a DivideByZero error will be thrown and should be caught by the
calling block with an output message indicating the error.
const int DivideByZero = 10;
double divide(double x, double y){
if ( 0 == y ){
}
return x/y;
}
...
try{
}
catch( int i ){
if(i==DivideByZero) {
cerr<<"Divide by zero error";
}
}
Example 3
The following C# example contains a function that divides two
numeric values without verifying that the input value used as the
denominator is not zero. This will create an error for attempting to divide
by zero, if this error is not caught by the error handling capabilities of
the language, unexpected results can occur.
(Bad Code)
Example
Language: C#
int Division(int x, int y){
}
The method can be modified to raise, catch and handle the
DivideByZeroException if the input value used as the denominator is
zero.
int SafeDivision(int x, int y){
try{
}
catch (System.DivideByZeroException dbz){
System.Console.WriteLine("Division by zero
attempted!");
return 0;
}
}
Description
