Книга: C# 2008 Programmer

Mathematical Operators

Mathematical Operators

C# supports five mathematical operators, shown in the following table.

One interesting thing about the division operator (/) is that when you divide two integers, the fractional part is discarded:

int num1 = 6;
int num2 = 4;
double result = num1 / num2;
Console.WriteLine(result); //---1---

Here both num1 and num2 are integers and hence after the division result only contains the integer portion of the division. To divide correctly, one of the operands must be a noninteger, as the following shows:

int num1 = 6;
double num2 = 4;
double result = num1 / num2;
Console.WriteLine(result); //---1.5---

Alternatively, you can use type casting to force one of the operands to be of type double so that you can divide correctly:

int num1 = 6;
int num2 = 4;
double result = (double)num1 / num2;
Console.WriteLine(result); //---1.5---

The modulus operator (%) returns the reminder of a division:

int num1 = 6;
int num2 = 4;
int remainder = num1 % num2;
Console.WriteLine(remainder); //---2---

The % operator is commonly used for testing whether a number is odd or even, like this:

if (num1 % 2 == 0) Console.WriteLine("Even");
else Console.WriteLine("Odd");

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