Let's examine the basic arithmetic operations in programming. We can add, subtract, multiply and divide numbers using the operators
Watch a video lesson about the arithmetic operators: https://youtu.be/XOtEuEUbA4M.
We can sum up numbers using the
var a = 5; var b = 7; var sum = a + b; // the result is 12
Subtracting numbers is done using the
var a = int.Parse(Console.ReadLine()); var b = int.Parse(Console.ReadLine()); var result = a - b; Console.WriteLine(result);
Here is the result of the execution of this program (with numbers 10 and 3):
For multiplication of numbers we use the
var a = 5; var b = 7; var product = a * b; // 35
Dividing numbers is done using the
/ operator. It works differently with integers and floating point numbers.
- When we divide two integers, an integer division is applied, and the obtained output is without its fractional part. Example: 11 / 3 = 3.
- When we divide two numbers and at least one of them is a float number, a floating division is applied, and the obtained result is a float number, just like in math. Example 11 / 4.0 = 2.75. When it cannot be done with exact precision, the result is being rounded, for example 11.0 / 3 = 3.66666666666667.
- The integer division by 0 causes an exception during runtime (runtime exception).
- Float numbers divided by 0 do not cause an exception and the result is +/- infinity or a special value NaN. Example 5 / 0.0 = ∞.
Here are a few examples with the division operator:
var a = 25; var i = a / 4; // we are applying an integer division: // the result of this operation will be 6 – the fractional part will be cut, // because we are dividing integers var f = a / 4.0; // 6.25 – floating division. We have set the number 4 to be interpreted // as a float by adding a decimal separator followed by zero var error = a / 0; // Error: Integer divided by zero
Let's examine a few examples for integer division (remember that when we divide integers in C# the result is an integer):
var a = 25; Console.WriteLine(a / 4); // Integer result: 6 Console.WriteLine(a / 0); // Error: divide by 0
Let's look at a few examples for floating division. When we divide floating point numbers, the result is always a float number and the division never fails, and works correctly with the special values +∞ and -∞:
var a = 15; Console.WriteLine(a / 2.0); // Float result: 7.5 Console.WriteLine(a / 0.0); // Result: Infinity Console.WriteLine(-a / 0.0); // Result: -Infinity Console.WriteLine(0.0 / 0.0); // Result: NaN (Not a Number), e.g. the result // from the operation is not a valid numeric value
When printing the values ∞ and -∞, the console output may be
?, because the console in Windows does not work correctly with Unicode and breaks most of the non-standard symbols, letters and special characters. The example above would most probably give the following result:
7.5 ? -? NaN