Java – Nested If

Nested If: Defining if block inside another if block.

Syntax:

if(condition){
	if(condition){
		if-if-Stat;
	}
	else{
		if-else-stat;
	}
}
else{
	if(condition){
		else-if-stat;
	}
	else{
		else-else-stat;
	}
}

Flow Chart:

Check Even Number or Not only if it is Positive

import java.util.Scanner;
class Code{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter number : ");
		int n = scan.nextInt();
		if(n>0){
			if(n%2==0)
				System.out.println("Even number");
			else
				System.out.println("Not even number");
		}
		else{
			System.out.println("Negative number given");
		}
	}
}

Biggest of two only if the two numbers or not equal

import java.util.Scanner;
class Code{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter a, b values : ");
		int a = scan.nextInt();
		int b = scan.nextInt();
		if(a!=b){
			if(a>b)
				System.out.println("a is big");
			else
				System.out.println("b is big");
		}
		else{
			System.out.println("a and b are equal");
		}
	}
}

Program to check the person can donate blood or not

Requirements: Age between 18 to 60 and Weight must be greater than 50

import java.util.Scanner;
class Code{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter age : ");
		int age = scan.nextInt();
		System.out.println("Enter weight : ");
		int weight = scan.nextInt();
		if(age>=18 && age<=60){
			if(weight>=50)
				System.out.println("Can donate blood");
			else
				System.out.println("Under weight");
		}
		els
			System.out.println("Not suitable age");
	}
}

Display Student Grade only if the student passed in all Subjects

import java.util.Scanner;
class Code{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter marks of 3 subjects : ");
		int m1 = scan.nextInt();
		int m2 = scan.nextInt();
		int m3 = scan.nextInt();
		if(m1>=40 && m2>=40 && m3>=40){
			int avg = (m1+m2+m3)/3;
			if(avg>=60)
				System.out.println("Grade-A");
			else if(avg>=50)
				System.out.println("Grade-B");
			else 
				System.out.println("Grade-C");
		}
		else{
			System.out.println("Student failed");
		}
	}
}

Check the Triangle is Equilateral or Isosceles or Scalene

• Equilateral: All sides are equal a==b==c
• Isosceles: Any two sides are equal a==b or a==c or b==c
• Scalene: No sides are equal a != b != c

import java.util.Scanner;
class Code{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter 3 sides of triangle : ");
		int a = scan.nextInt();
		int b = scan.nextInt();
		int c = scan.nextInt();
		if(a==b && b==c)
			System.out.println("Equilateral");
		else if(a==b ||a==c||b==c)
			System.out.println("Isosceles");
		else
			System.out.println("Scalene");
	}
}

Display days for the specified month

import java.util.Scanner;
class Code
{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		System.out.println("Enter Month number : ");
		int n = scan.nextInt();
		if(n>=1 && n<=12){
			if(n==2)
				System.out.println("28 days / 29 days");
			else if(n==4 || n==6 || n==9 || n==11)
				System.out.println("30 days");
			else
				System.out.println("31 days");
		}
		else{
			System.out.println("Invalid month number");
		}
	}
}