# Convert Decimal to Binary Using Recursion Using Python Codes

## Convert Decimal to Binary Using Recursion Using Python Codes

Technology: Problem is to write a python program to  convert decimal to binary using recursion. This Post we  will learn how to write a program that will  allow us to convert a decimal number into a   binary number using a recursion method first  of all talking about what are decimal numbers   let’s understand that decimal numbers are  all the numbers that we have from 0 to 9   and all the other numbers that we have  are the combination of these 10 numbers.

### Convert Decimal to Binary

Not talking about the binary number binary numbers  are two numbers that is 0 and 1 where 0 stands   for off and 1 stands for on now lastly talking  about the recursion recursion is a process in   which a function call itself inside a function  now let’s talk about all of them one by one first of all talking about decimal numbers decimal  numbers are 0 1 2 3 4 5 6 7 8 and 9. so these are   our decimal numbers and all the other numbers  are created by these nine numbers only these 10   numbers only right next talking about the binary  numbers so binary numbers are 0 and 1 that means.

There are two numbers in the binary numbers here  in the decimal numbers we have 10 numbers in total   okay lastly talking about the recursion so  recursion is a process where a function calls   itself inside a function now what do we need to  do we need to create a program which will convert   a decimal number into a binary number using  a process of recursion first of all talking   about converting a decimal number into a binary  number so when we do it on a paper that means   when we do it on the math how do we do it suppose  we have any number let’s say it’s 15 so how do.

Convert it into a binary number we need to divide  it by 2 that means so binary term over here means   2. so any number if you take any decimal number  if you take if you want to convert it into a   binary number then you have to divide it  by 2 when you divide it by 2 you get the   output 7 over here that means 2 times 7  is 14 and we get the 1 remainder right   similarly again we will divide it so 2 times 3  is 6 and we get 1 as the remainder then 2 times   1 is 2 and we’ll get the remainder as 1. now what  will be the binary number over here the binary.

Number will be this number over here so these  numbers that mean these string over here will   be our binary number so the binary number for 15  will not be 1 1 1 1 in this way but it will be 1   then this one then this one and then this one  that means when we write the binary string we   go all the way opposite so that means our  binary number for 15 would be 1 1 1 and 1.   similarly if i do it with any other number let’s  say if i do it with 10 so if i’ll write 2 so it   will be 5 and the remainder would be 0 2 2 times  is 4 remainder would be 1 2 1 time is 2 and the   remainder would be 0 right now what will be the  output that means what will be the binary number.

Of 10 it won’t be 0 1 0 1 it will it will be 1 0 1  0 this is how a binary string is written down this   is how we create a binary number now this is in  the math what if we want to do it in the python so   so for doing it in a python we have a very simple  method to convert our decimal number to binary   all we need to do is that we need to create a  function d e f and i want to convert it from   decimal to binary so d to b i’ll be writing  it so d to b is the name of my function   inside i’ll be passing a variable called as n  what do i need to do over here is now that if.

My n number is greater than 1 in that condition  whatever that number is suppose that number is   let’s say 12 okay so what do i need to do i need  to do the flow division of it to get the to get   the quotient over here so number flow division 2  and we have to put it inside d2 b that means he   will call this function over and over again till  the value is less than one okay after this here   what we need to do we need to print and model  is two that means remainder of this sort well.

When divided by two whatever remainder we’ll get  so we’ll get the remainder zero over here that 12   6 time is 12 and we’ll get the remainder 0 over  here that means the remainder 0 will come over   here then we will write end is equals to open  close quotations to again i trade this that   means this is this will work like a function  over here that means it will call itself again   that means d to b is a function which is calling  itself again inside the function that is our   process of recursion that it is calling  itself inside the function now next time.

What d to b will be it will be our 6 so 6 when  divided by 2 and 6 modulus 2 that would be our   2 3 times is 6 remainder is 0 again so next value  would be 0 again so we have now 0 and 0. now this   time we have 3 so 3 floor division 2 would be 1  and the remainder over here will also be 1 that   3 when divided by 2 gives us 1 that 2 1 is 2 and  the remainder is 1 so next value would be 1 and   lastly the last value the last remaining value  will again become 1 so the value would not be 0   0 1 1 it will be 1 1 0 and 0 this is how it will  work now let’s put this similar logic inside our.

Program so i’ll be writing def convert binary  because we want to convert it to binary so i’ll   be creating a function that is called as convert  binary and i will be passing a parameter called as   n over here inside this i’ll be giving a condition  that if n is greater than one only if n is greater   than one in that condition what do we need to  do we need to call this function convert binary   and inside we have to pass n flow division  two why every time we are taking the value   two because we have to convert it into a binary  and the word binary means 2 over here and then.

We’ll be printing n modulus 2 that means what is  the remainder of n when it is divided by 2 comma   end is equals to open close quotations lastly all  we need to do is take the input from the user for   the n so n is equals to int input enter a number  here next we need to print the converted value   in binary is i’ll put a call on over here and i’ll  call the function in the next line that is convert   binary and inside i’ll pass the value let’s say i  want to check it for number 15 we know for number.

15 the value was 1 1 1 1 let’s say if our program  says the same as well so i don’t have to write 15   actually over here because i’m taking the user  inputs i’ll be writing n only so if i run it   if i write 15 over here it gives me the converted  value in binary is 1 1 1 1 that means our program   is working perfectly fine and if i check it  for 12 for 12 we found out that the value was   double one double zero let’s see if it is double  one double zero or not so let’s run and if i write   12 it says double one double zero that means  our method over here is working perfectly fine   so all we needed to do was create a function  called as convert binary and pass a parameter   n and we need to give a condition that only if  n is greater than one in that condition.

Will do we will convert the binary that means  we’ll call the function again and whatever is   the quotient of n when divided by 2 that means in  flow division 2 will give us the quotient whatever   the quotient will be there that will be our value  of next n and we will print what we will print the   modulus of n when divided by 2 that means n when  divided by 2 whatever remainder gives.