if Statement

1. What is an if Statement?

An if statement lets a program run a block of code only when a certain condition is true. If the condition is false, that block is simply skipped.

2. Why is it used?

Programs rarely do the exact same thing every time — they need to react differently depending on the situation. The if statement is the most basic way to make a program take a decision.

3. Real-Life Example

Think of a simple rule: "If it is raining, carry an umbrella." You only pick up the umbrella when the condition (raining) is true. If it's not raining, you simply skip that action.

4. Syntax

java
if (condition) {
    // code runs only if condition is true
}

5. Example Program

java
public class IfDemo {
    public static void main(String[] args) {
        int marks = 80;
        if (marks >= 35) {
            System.out.println("You passed!");
        }
    }
}

Output:

You passed!

6. Key Points to Remember

• The condition inside if must evaluate to a boolean (true or false).
• Curly braces are optional for a single statement, but using them is a good habit that avoids bugs later.
• If the condition is false and there's no else, the program simply moves to the next line.