Why is this so simple code compiled error?

[ImLazy]

Code: Select all

#include <iostream>
#include <cmath>

using namespace std;

int main() {
    int a = -1;
    int b = abs(a);
    cout << b << endl;
    return 0;
}

[sumankar]

Code: Select all

#include <cmath>

should've been

Code: Select all

#include <cstdlib>

man for abs.

[misof]

man for abs.

And in case you only have windoze and no man pages, google for "man abs"

[ImLazy]

I don't quite understande what is man page.
At least now I know I should include <cstdlib> instead of <cmath>. Thank you.

[misof]

I don't quite understande what is man page.
At least now I know I should include <cstdlib> instead of <cmath>. Thank you.

"man" is short for manual, this is the standard *NIX way of accessing simple text-based documentation to almost everything. The most common are man pages for programs, but there are also man pages for C functions, system calls, and many other things.