c++ Save Int with leading zeros to String, NOT displaying them

Question

I can format an Int to display a number with leading zeros, but I can't figure out how to save an Int with the zeros to a string.

Reason: Loading image files that end in "..0001" "..0002" ... "..0059" etc.

I have this, but it doesn't work:

int a;
for(int i = 1; i < imgArraySize + 1; i++)
{
    cout << setw(4) << setfill('0') << i << '\n';
    cin >> a;
    string aValue = to_string(a);

    imageNames.push_back(string("test_images" + aValue + ".jpg"));
}

possible duplicate of [Convert a number to a string with specified length in C++](http://stackoverflow.com/questions/225362/convert-a-number-to-a-string-with-specified-length-in-c) — Cory Kramer, Oct 21 '14 at 12:14

Marco A. · Accepted Answer · 2014-10-21T14:05:23.027

4

You can apply the same formatting with a stringstream

std::ostringstream ss;
ss << std::setw(4) << std::setfill('0') << a;
std::string str = ss.str();
std::cout << str;

Live example

edited Oct 21 '14 at 14:05

answered Oct 21 '14 at 12:15

Marco A.

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was about to post the same :/ just saw the question too late – deW1 Oct 21 '14 at 12:16
Why `std::stringstream` instead of `std::ostringstream`? – James Kanze Oct 21 '14 at 13:59

c++ Save Int with leading zeros to String, NOT displaying them

1 Answers1