Using Decision Statements in C#

Using the ?: Operator or ternary operator and If Else

C# performs the statements in a program in a sequential manner. However, you frequently need to specify that alternative statements should run depending on the value of an expression or a Boolean condition. To achieve this ,C# provides conditional decision statements. Explain how to use the if else statement.

1. Using If Else

2. Using ?: operator.

3. Using switch statement

If else

If ([Condition]) //Code to Execute

.If ([Condition])

{

//If condition is true

//Code to Execute

}

.If ([Condition1] && [Condition2])

{

//If condition is true

//Code to Execute

}

.If ([Condition1] || [Condition2])

{

//If condition is true

//Code to Execute

}

if statements are very useful when you want to execute a code statement based on a condition. The basic syntax for a one-way if statement is shown in the following code example.

if ([condition]) [code to execute]

if the expression [condition] evaluates to a Boolean true value, [codeto execute] is executed. Notice that the condition must be enclosed in parentheses.You can execute more than one code statement. To do this, you delimit the code to run by using braces. This extends the syntax as the following code example shows.

if ([condition])

{

[code to execute if condition is true]

}

If(a>50)

{

C=a+b;

}

If Else statement

Provides additional code block to execute if [Condition] is evaluates to boolean false

If([Condition])

{

//Execute code

}

Else

{

//Else code to execute

}

Using the ?: Operator or ternary operator

As an alternative to using the if else statements, in some simple cases, you can use

the “?: “ ternary operator.The basic syntax to use the ?: operator is shown in the following code example.

Type result = [condition] ? [true expression] : [false expression]

If the expression [condition] evaluates to true, [true expression] is executed, but if the [condition] evaluates to false, [false expression] is executed.The following code example shows an example of using the ?: operator to check the value of a string, and then return a response.

string penColor = "green";

string response = (penColor == "red") ? "You have a red pen" :"You do not have a red pen";