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Sergio Ramos
Asked: 2020-03-12 10:03:02 +0800 CST 2020-03-12 10:03:02 +0800 CST

Show leading zeros of an integer in C++

  • 772

Hello, I have a 4-digit integer which sometimes, for example, will be envede, sometimes it will have zeros to its left, but the problem is that I don't know how to show the zeros to the left, suppose I have the following integer:

0382

How could I do to show it with a cout or a printf the zeros on its left since my number for example will be four characters. Or sometimes it will have more zero as I will be able to show the leading zeros. In my attempt I will make a cout:

int i;
i=0382;
cout << i;

But it will show me as 382 how could I do to show these zeros?

c++

3 Answers

  1. You can use printfinstead of cout.

    #include <iostream>
using namespace std;

int main()
{
   int i;
   i = 382;
   printf("%04d\n", i);
   return 0;
}
    • 4

  2. includes the libraryiomanip

    int i = 382;
std::cout << std::setfill('0') << std::setw(4) << i;

    Putting 0 in an integer is useless because they are ignored... Zeros are added when printing the value

    • 3
  3. Best Answer

    You can make use of cout.filland cout.width.

    #include <iostream>
using namespace std;

int main() {
    // your code goes here

    int i;
    i = 382;

    cout.fill  ('0');    
    cout.width ( 4 );
    cout << i;

    return 0;
}

    ideoneTest

    • 3