Basically, arithmetical operators (+, -, *, /) are the same as the mathematical ones. However, there are a few things to point out.

The most important thing to watch out is the kind of result you are expecting. If you will use two integers to perform a division, do not expect to get a real number, do not expect to get rounding, or any fractional part. For example, using integers, 7 / 2 = 3, not 4, not 3.5

Second thing to watch out about arithmetical operators when used with integer types is ** division by 0. **Whenever you will try to divide an integer by 0, you will get a special kind of error, an exception called

**DivideByZeroException**.Next point, whenever you want to get the remainder of a division between two integers, use % operator. In math, 9 / 4 = 2, remainder 1. In C#, you get the same result using 9 % 4.

When dealing with division between two numbers, of which at least one is a real number, the result is a real number, not integer. Example: 5.0 / 2 = 2.5

Unlike integers, you are allowed to divide real numbers by 0.0, and the result is positive infinity, negative infinity or a special kind of result named * NaN, *which means “not a number”, and represents an invalid value.

*The concepts explained in this lesson are also shown visually as part of the following video:*

**EXERCISES**

**1.** Write an expression that checks whether an integer is **odd or even**.

Solution

Guidelines: Take the

**remainder of dividing the number by 2**and check if it is 0 or 1 (respectively the number is odd or even).

**Use % operator**to calculate the remainder of integer division.

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static void Main(string[] args) { int number = 23; bool even = number % 2 == 0 ? true : false; Console.WriteLine("{0} is even? {1}", number, even); } |

Tags: arithmetical operators, operators