We are all aware of what is an if-else statement, still for a revision we will go through it:

• Use if to specify a block of code to be executed, if a specified condition is true.
• Use else to specify a block of code to be executed, if the same condition is false.
• Use else if to specify a new condition to test, if the first condition is false.

Java program to implement If-else statement:

import java.util.Scanner;

class IfElse {
  public static void main(String[] args) {
    int marksObtained, passingMarks;

    passingMarks = 40;

    Scanner input = new Scanner(System.in);

    System.out.println("Input marks scored by you");

    marksObtained = input.nextInt();

    if (marksObtained >= passingMarks) {
      System.out.println("You passed the exam.");
    }
    else {
      System.out.println("Unfortunately you failed to pass the exam.");
    }
  }
}

OUTPUT:

#javac IfElse.java
#java IfElse

Input marks scored by you
58
You passed the exam.

Java program to implement nested If-else statement:

import java.util.Scanner;

class NestedIfElse {
  public static void main(String[] args) {
    int marksObtained, passingMarks;
    char grade;

    passingMarks = 40;

    Scanner input = new Scanner(System.in);

    System.out.println("Input marks scored by you");

    marksObtained = input.nextInt();

    if (marksObtained >= passingMarks) {

      if (marksObtained > 90)
        grade = 'A';
      else if (marksObtained > 75)
        grade = 'B';
      else if (marksObtained > 60)
        grade = 'C';
      else
        grade = 'D';

      System.out.println("You passed the exam and your grade is " + grade);
    }
    else {
      grade = 'F';
      System.out.println("You failed and your grade is " + grade);
    }
  }
}

OUTPUT:

javac NestedIfElse.java
java NestedIfElse

Input marks scored by you
58
You passed the exam and your grade is D