Replace all 0’s with 1 in a given integer using Java

May 28, 2022

Replace all 0’s with 1 using Java 

In this article we will create a  program to replace all 0’s with 1 using java. For this purpose we will ask the user to enter a positive number and check each digit one by one that it is equal to 0 or not. If the digit is equal to 0 then replace the digit by 1, and else no change.

Replace 0 with 1

Implementation

  • We will convert the integer into string.
  • Then we will convert it into list and then we will traverse through the list.
  • Wherever we find a ‘0’ we will replace with ‘1’.
Replace all 0's with 1 using java

Algorithm

  • Take Input in num and initialize a variable num with with value 0
  • If num is equals to zero then update the value of num2 to 1
  • Iterate using a while loop until num is greater then 0
  • For each iteration initialize a variable rem and store unit digit of num
  • If rem equals to 0 then set rem to 1
  • Set num to num divide by 10 & num2 equals to num2*10+rem
  • Reverse and print num2

Java code

Run 
//Java program to replace all 0's with 1 in a given integer  : 
import java.util.Scanner;
public class Main
{
	public static void main(String[] args)
	{
		//scanner class declaration
		Scanner sc = new Scanner(System.in);
		//input from the user		
		System.out.print("Enter the number : ");		
		int number = sc.nextInt();
		//convert the number to string and then calculate its length
		String str = Integer.toString(number);
		int len = str.length();
		String str1 = "";
		//use the logic to replace all 0's with 1 in a given integer
		for(int i = 0 ; i < len ; i++)
		{
			if(str.charAt(i) == '0')
				str1 = str1 + '1';
			else
				str1 = str1 + str.charAt(i);	
		}
		System.out.println("Converted number is: "+str1);
		//closing scanner class(not compulsory, but good practice)
		sc.close();									
	}
}

Output

Enter the number : 706120678
Converted number : 716121678

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2 comments on “Replace all 0’s with 1 in a given integer using Java”


  • Satendra

    import java.util.*;public class Main
    {
    public static void main(String[] args)
    {
    String str=””;
    String str2=””;
    System.out.println(“enter”);
    Scanner s= new Scanner(System.in);
    str=s.nextLine();
    for(int i=0; i<str.length();i++){
    if(str.charAt(i)=='0'){
    str2=str2+'1';

    }
    else{
    str2=str2+str.charAt(i);

    }

    }
    System.out.println(str2);
    }
    }

    1

  • Asif

    import java.util.*;

    public class Main
    {
    static int replace(int number)
    {
    // Base case for recursion termination
    if (number == 0)
    return 0;
    // Extract the last digit and change it if needed
    int digit = number % 10;
    if (digit == 0)
    digit = 1;
    // Convert remaining digits and append the last digit
    return replace(number/10) * 10 + digit;
    }
    static int Convert(int number)
    {
    if (number == 0)
    return 1;
    else
    return replace(number);
    }

    public static void main(String[] args)
    {
    int number;
    Scanner sc = new Scanner(System.in);
    System.out.print(“Enter the number : “);
    number = sc.nextInt();
    System.out.print(“Number after replacement : “);
    System.out.print(replace(number));
    }
    }

    0