What causes 'arithmeticexception: / by zero' in java?

This runtime exception is thrown when code attempts to divide by zero. In Java, dividing by zero in integer arithmetic will throw this exception. Example:

int result = 5 / 0;

Solution:

int divisor = 0;
if(divisor != 0) {
    int result = 5 / divisor;
}

Always include checks in your code to prevent division by zero especially when dealing with user input or dynamic values.