Duck Number in JAVA

Duck Number

Duck Number : 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, 2357,1253 etc are not. 

Input     : 50401

Output  : It is a Duck Number

Input     : 04208

Output  : It is not a Duck Number

Input     : 4231

Output  : It is not a Duck Number

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Algorithm and Program given below :-

Algorithm :-

• Input a number in a string variable

• In a variable find its length

• Using if statement check if it has 0 at 1st position (i.e. at 0th position in string) using "charAt"

• If it has 0 than display "It is not a duck number"

• Else using for loop extract each character from 2nd position (i.e. at 1st position of string).

• Now check if the character is '0' or not 

• If it is '0' than use break statement and display "It is Duck Number"

• Else display "It is not a Duck Number"

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Program :-

import java.io.*; import java.util.*; class Duck {     public static void main(String args[])     {             Scanner in = new Scanner(System.in);         String str;         char ch;         int k=0,l,i;         System.out.println("Enter Number ");         str= in.nextLine(); // Input number as a String         l= str.length(); // storing length of the number         if(str.charAt(0)=='0') // if at 0th position 0 is present         {             System.out.println("It is not a Duck Number "+str); // print number is not duck no.         }         else         {             for(i=1;i<l;i++)             {                 ch=str.charAt(i); //extracting each character from 1st position                 if(ch=='0') // if is found at any position                 {                     k=1; //defining value of k=1                     break;                 }             }             if(k==1)             {                 System.out.println("It is a Duck Number : "+str); //printing duck number             }             else             {                 System.out.println("It is not a Duck Number : "+str); // printing not a duck no.             }         }     } // end of main method } // end of class

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Note : The program is written in the easiest way possible so try to understand it. If you face any problem in understanding this program than feel free to contact/comment.

Duck Number Source Code : Click here

Program Video : Watch Now

All the Best :)

Keep Learning :)