Evaluate conditions with Boolean expressions

Completed

Tip

See the Text and images tab for more details!

Before your code can make a decision, it needs a way to ask a question and get a yes-or-no answer. C# answers this kind of question with Boolean expressions and comparison operators.

Boolean expressions

A Boolean expression is any code that evaluates to true or false. The bool data type stores exactly one of these two values:

bool isGameOver = true;
bool isWinner = false;

Comparison operators

Comparison operators compare two values and produce a Boolean result:

Operator	Meaning	Example	Result
==	Equal to	5 == 5	true
!=	Not equal to	5 != 3	true
>	Greater than	10 > 3	true
<	Less than	3 < 10	true
>=	Greater than or equal to	5 >= 5	true
<=	Less than or equal to	4 <= 3	false

Note

Don't confuse the equality operator (==) with the assignment operator (=). Use == to compare two values, and = to assign a value to a variable.

The if statement

An if statement runs a block of code only when its Boolean expression is true. The block of code is defined by curly braces { }:

int total = 17;

if (total >= 15)
{
    Console.WriteLine("You win!");
}

If the expression total >= 15 is false, C# skips the code block entirely and continues with the next line.

You can try this yourself in the C# Code Editor.