if-else

1. What is if-else?

if-else extends the basic if statement by adding an alternative block of code that runs when the condition is false. Exactly one of the two blocks will run — never both, never neither.

2. Why is it used?

Many decisions have exactly two outcomes — pass or fail, eligible or not eligible. if-else handles both possibilities cleanly in one structure.

3. Real-Life Example

Think of an exam result: "If marks are 35 or above, you pass; otherwise, you fail." Both outcomes are covered — there's always a result either way.

4. Syntax

java
if (condition) {
    // runs if condition is true
} else {
    // runs if condition is false
}

5. Example Program

java
public class IfElseDemo {
    public static void main(String[] args) {
        int marks = 20;
        if (marks >= 35) {
            System.out.println("Pass");
        } else {
            System.out.println("Fail");
        }
    }
}

Output:

Fail

6. Key Points to Remember

• Exactly one block runs — if or else — never both.
• The else block has no condition of its own; it simply handles "everything else."
• Great for situations with only two possible outcomes.