Question

The following program segment calculates and displays the factorial of a number. [Example: Factorial of 5 is 1 x 2 x 3 x 4 x 5 = 120]

   int p, n = 5, f=0; 
   for (p = n; p>0; p--)
   f*=p;
   System.out.println(f);

Name the type of error if any; correct the statement to get the desired output.

Answer 1

int p, n = 5, f = 1;

• The program segment has a logical error.
• Type of Error: Logical Error.
• The variable f is initialised to 0. Since any number multiplied by zero is zero, the calculation f *= p will always result in 0. To calculate a factorial, the initial value of the product variable must be 1.
• To get the desired output, change the initialisation of f from 0 to 1.