Exercise:
Write a Java Program to display Armstrong number between two intervals.
Click Here to View the Solution!
public class ArmstrongNumber {
public static void main(String[] args) {
int low = 999, high = 99999;
for(int number = low + 1; number < high; ++number) {
if (checkArmstrong(number))
System.out.print(number + " ");
}
}
public static boolean checkArmstrong(int num) {
int digits = 0;
int result = 0;
int originalNumber = num;
// Calculates number of digits.
while (originalNumber != 0) {
originalNumber /= 10;
++digits;
}
originalNumber = num;
// result is sum of nth power of its digits
while (originalNumber != 0) {
int remainder = originalNumber % 10;
result += Math.pow(remainder, digits);
originalNumber /= 10;
}
if (result == num)
return true;
return false;
}
}
Click Here to View the Output!
1634 8208 9474 54748 92727 93084
Click Here to View the Explanation!
- This program is used for displaying all the Armstrong Numbers between two intervals
low
andhigh
by using a function in Java. - The function used in the program
checkArmstrong()
is created within the program for finding all the Armstrong numbers between two integers. - The user-defined function “
checkArmstrong()
” takes the variablenum
as an argument and gives a Boolean value in return. - Initially, for the intervals, tow integer variable low and high are set as
low = 999
andhigh = 99999
. - A for loop holds an initialization (
number = low + 1
), a conditional expression (number < high
) and an expression to update a variable (++number
). This loop allows the program to check every number in the interval low and high. - In the user-defined
checkArmstrong
function, the first while loop is used to calculate the number of digits in theoriginalNumber
and stores it in the variabledigit
. - Whereas, the second while loop is used to calculate the remainder of the
originalNumber
and the result by powering the remainder with the number of digits in every iteration. - After the loop exits, both the result and the number are compared. If both are equal, the number is an Armstrong number the function will return true else, false.
- The
checkArmstrong
function applied on the number will print the output within themain()
method according to the value returned by its defined function.