Control Flow

If Statement in C#

To control decision making by checking true/false statements resulting in different executions of code if result is true and if the result is false.

Syntax

if (booleanExpression) {  
   //Executes when booleanExpression holds true
} 

else if (booleanExpression2) { 
   //Executes when booleanExpression2 holds true 
} 

else { 
   //Executes when neither booleanExpression nor booleanExpression2 are true 
}

Notes

booleanExpression(s) are those that result in either a true or false output. They are created using comparing operators (==, >, =, <=, !=).

There can also be multiple boolean expressions within the parentheses (booleanExpression). The boolean expressions are connected through logical operators (&&, ||, !).

Else if statements allow for another boolean expression check within the overall if structure.

Else statements result in the execution of code if the if statement (and if applicable, the if else statement(s)) do not hole true.

Nested if (else) statements are also possible and are the inclusion of another (or multiple) if statements within an if statement structure.

Example

if (counter >= 30) { 
   Console.WriteLine("Counter is greater than or equal to 30."); 
} 
else if (counter ==20) { 
   Console.WriteLine("Counter is at 20."); 
   counter++; 
} 
else { 
   counter++; 
}