Java If-else Statement

if-else is how a program chooses. Real life is not one straight list of steps. Marks can be pass or fail. A number can be even or odd. The program must look at a condition and pick one path. That condition in Java must be true or false — not a lone number like old C. Write if (marks >= 40), not if (marks).

if (condition) { ... } runs only when the condition is true. else is the backup when it is false. else if adds more checks from top to bottom. The first match wins; later else if lines are skipped. Think of it as a teacher checking a paper: first 40+ pass, else fail. Don’t check fail before pass if your story starts at 40.

Let’s take this tiny example on the board. int n = 7; if (n % 2 == 0) print Even; else print Odd. % is remainder. 7 divided by 2 leaves 1, not 0, so the if is false. else runs. Output: Odd. Now change n to 8 in your head. 8 % 2 is 0, if is true, output Even. If you can do that without compiling, you understand if-else.

Same idea with marks. int marks = 35; if (marks >= 40) Pass; else Fail. 35 is not >= 40, so Fail. marks = 72 → Pass. Always pick a sample value and say the branch out loud before you type. That is the classroom habit. Jumping into code with no dry-run is how bugs multiply.

Two mistakes I see every year. One: a semicolon after if (n % 2 == 0); — that empty if ends immediately, and the next { } always runs. Two: writing = inside if when you meant ==. = assigns. == compares. if (n = 2) is not what you wanted, and Java often refuses it because it is not boolean.

else if is for more than two buckets: if marks >= 75 Distinction else if marks >= 40 Pass else Fail. Check from the top. A student with 80 matches the first if and never looks at else if. Order matters. Put the strictest check first when the ranges overlap.

Diagram

marks >= 40 ?
       /        \
     yes         no
      │           │
    Pass        Fail

Exam tip

Take marks = 35 and 72. Say which branch runs, then write the if-else.

Example

// Java If-else
public class Main {
  public static void main(String[] args) {
    int n = 7;
    if (n % 2 == 0) {
      System.out.println("Even");
    } else {
      System.out.println("Odd");
    }
  }
}

Java If-else Statement — take n = 7. 7 % 2 is 1, not 0, so if is false. else runs. Output: Odd. Now n = 8 → Even.

Short notes

Defif runs a block only when the condition is true.
Ruleelse is the backup. else if checks from top; first match wins.
RememberCondition must be boolean. Use n % 2 == 0, not a lone number.
TrapSemicolon after if (cond); makes the next block always run.
Useeven/odd, pass/fail, discount.

Java If-else Statement

Diagram

marks >= 40 ?
       /        \
     yes         no
      │           │
    Pass        Fail

Exam tip

Take marks = 35 and 72. Say which branch runs, then write the if-else.

// Java If-else public class Main { public static void main(String[] args) { int n = 7; if (n % 2 == 0) { System.out.println("Even"); } else { System.out.println("Odd"); } } }

Java If-else Statement

Example

Short notes

Questions

Java If-else Statement

Example

Short notes

Questions