Java Program to check ‘Duck’ number

Write a Program in Java to input a number and check whether it is a Duck Number or not.

A Duck number is a number which has zeroes present in it, but there should be no zero present in the beginning of the number. For example 3210, 7056, 8430709 are all duck numbers whereas 08237, 04309 are not.

class Duck_No
public static void main(String args[])throws IOException
BufferedReader br=new BufferedReader(new InputStreamReader(;
System.out.print(“Enter any number : “);
String n=br.readLine(); //inputting the number and storing it in a String
int l=n.length(); //finding the length (number of digit) of the number
int c=0; //variable for counting number of zero digits
char ch;
for(int i=1;i<l;i++) { ch=n.charAt(i); //extracting each digit and checking whether it is a ‘0’ or not if(ch==’0′) c++; } char f=n.charAt(0); //taking out the first digit of the inputted number if(c>0 && f!=’0′)
System.out.println(“It is a duck number”);
System.out.println(“It is not a duck number”);
Enter any number: 4013
It is a duck number
Enter any number: 0134
It is not a duck number
Enter any number: 67300987
It is a duck number