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So I'm making a binary->decimal program where i need to target a specific digit in the number which is inputed, so for instance if the input is 100110110, how do i target the fourth digit, in this case obviously being 1, and the fifth, sixth, ... how many ever digits there are?

Tejas K
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  • [How do you set, clear, and toggle a single bit in C/C++?](http://stackoverflow.com/questions/47981/how-do-you-set-clear-and-toggle-a-single-bit-in-c-c?rq=1) – Pavel P Apr 27 '17 at 18:08
  • do you have the binary in a string or in an int / long – pm100 Apr 27 '17 at 18:12
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    Possible duplicate of [How do you set, clear, and toggle a single bit in C/C++?](http://stackoverflow.com/questions/47981/how-do-you-set-clear-and-toggle-a-single-bit-in-c-c) – François Andrieux Apr 27 '17 at 18:14

2 Answers2

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If the input is a binary string, store the input in a string and process it using a loop

string num = "1001010";
int l = num.length();

for(int i=0; i<l; i++) {
    // num[i] is the (i+1)th bit from left;
}
Rajeev Singh
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how many ever digits there are?

these are called bits. To find number of bits in a variable use sizeof operator that returns number of bytes.

sizeof(variable) * 8

how do i target the fourth digit

you can test a bit with operator&:

if (8 == (variable & 8))
    ...

There are already detailed answers on how to do that: How do you set, clear, and toggle a single bit in C/C++?

Community
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Pavel P
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  • This answer does not address how to read or write individual bits, or access them as OP puts it. – François Andrieux Apr 27 '17 at 18:11
  • @FrançoisAndrieux why would you address something that have been done properly years ago. I added link in the comment. – Pavel P Apr 27 '17 at 18:13
  • If you know that this question has already been correctly answered before and have a link to that answer, why did you not vote for duplicate? – François Andrieux Apr 27 '17 at 18:14
  • @FrançoisAndrieux Because it asks also about number of digits. And you vote down because of what?.. – Pavel P Apr 27 '17 at 18:15
  • can someone link me something about the basics of bits, havent read into them much; also is there any library you need to include for bits? – Tejas K Apr 27 '17 at 18:17
  • @TejasK Google for `Bits Manipulation in C` or something like that. This is usually covered in beginner programming books. No library is needed for that – Pavel P Apr 27 '17 at 18:19