C++ if else Statement

Decision Making in C++ helps to write decision-driven statements and execute a particular set of code based on certain conditions.

The if statement alone tells us that if a condition is true it will execute a block of statements and if the condition is false it won’t. But what if we want to do something else if the condition is false. Here comes the C++ else statement. We can use the else statement with if statement to execute a block of code when the condition is false.

Syntax

if (condition)
{
    // Executes this block if
    // condition is true
}
else
{
    // Executes this block if
    // condition is false
}

Working of if-else statement

1. Control falls into the if block.
2. The flow jumps to Condition.
3. Condition is tested.
   1. If Condition yields true, goto Step 4.
   2. If Condition yields false, goto Step 5.
4. The if-block or the body inside the if is executed.
5. The else block or the body inside the else is executed.
6. Flow exits the if-else block.

Flowchart if-else:

Examples of if else statement in C++

Example 1:

Below program demonstrates the use of if else statements in C++.

i is 20
Outside if-else block

Explanation:

• Program starts.
• i is initialized to 20.
• if-condition is checked. i == 10, yields false.
• flow enters the else block.
• “i is 20” is printed
• “Outside if-else block” is printed.

Example 2:

Another program to illustrate the use of if else in C.

i is greater than 15

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