Java program to print all the natural numbers from 1 to N can be written in both iterative and recursive methods. In the iterative method, the task can be performed by using for loop, while loop and do-while loop. Here, all the Java programs using different loops have been covered to print the natural numbers from 1 to N (1, 2, 3, ..., N).
1. Java Program & output to Print First N Natural Numbers
Code has been copied
/************************************************** alphabetacoder.com Java program to print all natual numbers from 1 to n using for loop**************************************************/import java.util.Scanner;
publicclassPrintNumbers {
publicstaticvoid main(String args[]) {
//System.in is a standard input stream// sc is the object
Scanner sc = new Scanner(System.in);
int n, i;
//take input of the number upto // which numbers will be printed
System.out.print("Enter the upper limit=");
n = sc.nextInt();
// iterate from 1 to n and print the number
System.out.print("First " + n + " natural numbers are : ");
for (i = 1; i <= n; i++) {
System.out.print(i + " ");
}
}
}
Output
Case 1:
Enter the upper limit=10
First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10
Case 2:
Enter the upper limit=5
First 5 natural numbers are : 1 2 3 4 5
/************************************************** alphabetacoder.com Java program to print all natual numbers from 1 to n using while loop**************************************************/import java.util.Scanner;
publicclassPrintNumbers {
publicstaticvoid main(String args[]) {
//System.in is a standard input stream// sc is the object
Scanner sc = new Scanner(System.in);
int n, i;
//take input of the number upto // which numbers will be printed
System.out.print("Enter the upper limit=");
n = sc.nextInt();
// iterate from 1 to n and print the number
System.out.print("First " + n + " natural numbers are : ");
i = 1;
while (i <= n) {
System.out.print(i + " ");
i++;
}
}
}
Output
Case 1:
Enter the upper limit=10
First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10
Case 2:
Enter the upper limit=5
First 5 natural numbers are : 1 2 3 4 5
/************************************************** alphabetacoder.com Java program to print all natual numbers from 1 to n using do-while loop**************************************************/import java.util.Scanner;
publicclassPrintNumbers {
publicstaticvoid main(String args[]) {
//System.in is a standard input stream// sc is the object
Scanner sc = new Scanner(System.in);
int n, i;
//take input of the number upto // which numbers will be printed
System.out.print("Enter the upper limit=");
n = sc.nextInt();
// iterate from 1 to n and print the number
System.out.print("First " + n + " natural numbers are : ");
i = 1;
do {
System.out.print(i + " ");
i++;
} while (i <= n);
}
}
Output
Case 1:
Enter the upper limit=10
First 10 natural numbers are : 1 2 3 4 5 6 7 8 9 10