If-Else Statement
1. Plain-English Idea (beginner)
If condition true → do this block, else → do that block. The only way to branch. Condition must be boolean (Java won't accept if(5) like C!).
int marks = 75;
if (marks >= 40) System.out.println("Pass"); // single line (no braces ok, risky!)
if (marks >= 40) { System.out.println("Pass"); } // block (safe style)
else { System.out.println("Fail"); }
if (marks >= 90) System.out.println("A"); // ladder (grade!)
else if (marks >= 75) System.out.println("B");
else if (marks >= 40) System.out.println("C");
else System.out.println("F");
Always use braces even for one line — prevents dangling-else bugs.
4. Practice (pass/fail + even/odd)
if (n % 2 == 0) System.out.println("even");
else System.out.println("odd");
5. Exam Points
- Ladder program (grades) + output trace — 5-7 marks, very frequent.
=vs==, dangling else — 3-5 marks, favourite traps.