Convert a binary number into a decimal number

[4wCjE3v7]

Here's the part of the codes where I tried to use boolean expression:

#include <iostream>
using namespace std;
int main()
{
  int num;
  cout << "8-bit Binary Number=";
  cin >> num;
  
  bool valid = true;
.
.
.
.
.
.
.
.
.
if (valid)
{
    cout << "Decimal Number = " << sum;
  }
}

May I know that how can I get started with the body?

Thanks for your guides!

[mokhi64]

this code converts a binary number to a decimal one.
you can use it as a function under your condition ( => if(valid) <= )

#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;
int main() {
	string bin;
	cin >> bin;
	int dec = 0;
	reverse(bin.begin(), bin.end());
	for (int i = 0; i < bin.size(); ++i) {
		dec += (int(bin[i]) - 48)*pow(2, i);
	}
	cout << dec;
	return 0;
}

[ats15]

I would use a string instead of an int for num.
Step 1. Check if you have 8 digits
Step 2. Check if all digits are 0 or 1
Step 3. Calculate sum (inside if(valid){ ... })

[4wCjE3v7]

Hi, mokhi64,
Thanks for your suggestions up there, but I'm just a beginner for c++ and have not gone to this extent yet. There are some code you written down I still understand yet.
So, may I know that how can I continue my code above from line 10 to if (valid)? thanks

[ZFalcon]

Yo Vampire ,
is this your assignment for programming subject or something?

[buffbill]

Can you convert from base 2 to base 10 manually?
If not each column starting from the right has double the value of the previous column. The first column has a value of 1, the next 2, the next 4 then 8,16,32,64,128,256,512,1024,2048.... and so on.
To convert to base 10 from base 2 : 01110101110000110100111.
you would get (starting from the right hand end) of the binary number:
1*1+1*2+1*4+0*8+0*16+1*32+0*64+1*128...and so on.
Now you need to write some code which will perform similarly; and post again if you have difficulties.