## Java || Snippet – How To Convert A Decimal Number Into Binary

This page will demonstrate how to convert a decimal number (i.e a whole number) into its binary equivalent. So for example, if the decimal number of 25 was entered into the program, it would display the converted binary value of 11001.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

```How To Count In Binary The "Long" Datatype - What Is It? Methods (A.K.A "Functions") - What Are They? While Loops Online Binary to Decimal Converter - Verify For Correct Results ```

If you are looking for sample code which converts binary to decimal, check back here soon!

``` Convert A Decimal Number Into Binary Java import java.util.Scanner; public class DecimalToBinary { // global variable declaration static Scanner cin = new Scanner(System.in); public static void main(String[] args) { // declare variables long decNum = 0; String binaryNum = ""; // use a string instead of an int to avoid // overflow, because binary numbers can grow large quick // display message to screen System.out.println("Welcome to My Programming Notes' Java Program.n"); // get decimal number from user System.out.print("Please enter an integer value: "); decNum = cin.nextLong(); if(decNum < 0) // if user inputs a neg number, make the binary num neg too { binaryNum = "-"; } // method call to convert decimal to binary binaryNum += DecToBin(decNum); // display data to user System.out.println("nThe integer value of "+ decNum + " = " + binaryNum + " in binary"); }// end of main public static String DecToBin(long decNum) { // use this string to save the binary number String binary = ""; if(decNum < 0) // if input is a neg number, make it positive { decNum *= -1; } // converts decimal to binary using division and modulus while(decNum > 0) { binary += (decNum % 2); decNum /= 2; } // return the reversed string to main return new StringBuffer(binary).reverse().toString(); } }// http://programmingnotes.org/ 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455 import java.util.Scanner; public class DecimalToBinary{ // global variable declaration static Scanner cin = new Scanner(System.in); public static void main(String[] args) { // declare variables long decNum = 0; String binaryNum = ""; // use a string instead of an int to avoid                   // overflow, because binary numbers can grow large quick // display message to screen System.out.println("Welcome to My Programming Notes' Java Program.n"); // get decimal number from user System.out.print("Please enter an integer value: "); decNum = cin.nextLong(); if(decNum < 0) // if user inputs a neg number, make the binary num neg too { binaryNum = "-"; } // method call to convert decimal to binary binaryNum += DecToBin(decNum); // display data to user System.out.println("nThe integer value of "+ decNum + " = " + binaryNum + " in binary"); }// end of main  public static String DecToBin(long decNum) { // use this string to save the binary number String binary = ""; if(decNum < 0) // if input is a neg number, make it positive { decNum *= -1; } // converts decimal to binary using division and modulus while(decNum > 0) { binary += (decNum % 2); decNum /= 2; } // return the reversed string to main return new StringBuffer(binary).reverse().toString(); }}// http://programmingnotes.org/ ```

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output
Note: The code was compiled 3 separate times to display different output

`====== RUN 1 ======`

``` Welcome to My Programming Notes' Java Program. Please enter an integer value: 5 The integer value of 5 = 101 in binary ====== RUN 2 ====== Welcome to My Programming Notes' Java Program. Please enter an integer value: -25 The integer value of -25 = -11001 in binary ====== RUN 3 ====== Welcome to My Programming Notes' Java Program. Please enter an integer value: 12345678910 ```

```The integer value of 12345678910 = 1011011111110111000001110000111110 in binary ```