ArithmeticException: Division by Zero

Why This Happens

In Java, dividing an integer by zero throws ArithmeticException. Note that dividing a floating-point number by zero does not throw this exception; it produces Infinity or NaN instead. This commonly occurs when a denominator comes from user input or a calculation that can produce zero.

The Problem

int total = 100;
int count = 0;
int average = total / count; // ArithmeticException: / by zero

The Fix

int total = 100;
int count = 0;
int average = (count != 0) ? total / count : 0;

Step-by-Step Fix

1. 1

   Identify the division

   Find the division or modulo operation on the failing line in the stack trace.

2. 2

   Trace the zero divisor

   Find where the divisor variable gets its value and why it is zero.

3. 3

   Add a zero check

   Check the divisor before dividing and handle the zero case with a default value or error message.