Java Program for Sum of First N Numbers

Java Program for Sum of First N Numbers using for loop

This java program is used to compute the sum of first n numbers using for loop.

Gets the limit value as user input and calculates the sum till limit value and prints the sum value.

import java.util.Scanner;

class SumTest {
	public static void main(String[] values) {
		int sum = 0, limit;
		Scanner sc = new Scanner(System.in);
		System.out.println("Calculates Sum of first n numbers");
		System.out.println("----------------------------------");
		System.out.print("Enter limit number:");
		limit = sc.nextInt();
		for(int i=1;i<=limit;i++){
			sum += i;
		}
		System.out.println("Sum of first '"+limit+"' numbers: " + sum);
	}
}

D:\Java_Programs>javac SumTest.java
D:\Java_Programs>java SumTest 
Calculates Sum of first n numbers
----------------------------------
Enter limit number:10
Sum of first '10' numbers: 55

Java Program for Sum of First N Numbers using while loop

This java program is used to compute the sum of first n numbers using while loop.

import java.util.Scanner;

class SumTest {
	public static void main(String[] values) {
		int sum = 0, limit;
		Scanner sc = new Scanner(System.in);
		System.out.println("Calculates Sum of first n numbers");
		System.out.println("----------------------------------");
		System.out.print("Enter limit number:");
		limit = sc.nextInt();
		int i=1;
		while(i<=limit){
			sum += i;
			i++;
		}
		System.out.println("Sum of first '"+limit+"' numbers: " + sum);
	}
}

D:\Java_Programs>javac SumTest.java
D:\Java_Programs>java SumTest 
Calculates Sum of first n numbers
----------------------------------
Enter limit number:9
Sum of first '9' numbers: 45

Java Program for Sum of First N Numbers using do while loop

This java program is used to compute the sum of first n numbers using do while loop.

import java.util.Scanner;

class SumTest {
	public static void main(String[] values) {
		int sum = 0, limit;
		Scanner sc = new Scanner(System.in);
		System.out.println("Calculates Sum of first n numbers");
		System.out.println("----------------------------------");
		System.out.print("Enter limit number:");
		limit = sc.nextInt();
		int i=1;
		do {
			sum += i;
			i++;
		}while(i<=limit);
		System.out.println("Sum of first '"+limit+"' numbers: " + sum);
	}
}

D:\Java_Programs>javac SumTest.java
D:\Java_Programs>java SumTest 
Calculates Sum of first n numbers
----------------------------------
Enter limit number:8
Sum of first '8' numbers: 36