In this tutorial, we will write a java program to convert decimal to binary without using array. Before that, you must have knowledge of the following topics in java.

**Binary number**

The binary numbers are based on 0 and 1, so it is a base 2 number. They are the combination of 0 and 1. For example, 1001, 110101, etc.

**Decimal Number**

These are the numbers with a base of 10, which ranges from 0 to 9. These numbers are formed by the combination of 0 to 9 digits such as 24, 345, etc.

Here is the chart where for the equivalent value of decimal and binary numbers.

**Example:**

`Input: 5 `

Output: 101

Input: 7

Output: 111

Now let us go through a program for the conversion of decimal to binary in java using a while loop.

**Java Program to convert Decimal to Binary using while loop**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | import java.util.Scanner; public class Main { public static void main(String[] args) { int i = 1, decimal, binary = 0, rem; Scanner sc = new Scanner(System.in); System.out.println("Enter a decimal number: "); decimal = sc.nextInt(); while (decimal != 0) { rem = decimal % 2; binary += i * rem; decimal /= 2; i *= 10; } System.out.println("Equivalent Binary Value: " + binary); } } |

**Output:**

`Enter a decimal number:`

10

Equivalent Binary Value: 1010