If Statement

An if statement is the simplest form of conditional logic.

It allows a program to execute a block of code only if a condition is true.

How an If Statement Works

Conceptually:

The program checks a condition
If the condition is true, the code inside the if block is executed
If the condition is false, the code is skipped

Example (Python)

age = 18

if age >= 18:
    print("You are allowed to enter.")

Explanation:

The condition age >= 18 is evaluated
If the condition is true, the message is printed

When to Use `if`

Use an if statement when:

you only care about one condition
there is no alternative action needed
you want to guard a piece of code

Summary

if checks a condition
Code runs only when the condition is true
It is the foundation of all conditional logic