How to check a string for digits

[Nick3306]

I need to check a string and make sure it only has digits. I know how to check certain positions inside the string with (isdigit(str[0])) but is there a way to check the whole thing at once?

[Aramil of Elixia]

isdigit(str.c_str())?

[maeriden]

isdigit() takes a char as argument, not a char*

I don't think that's possible

[Aramil of Elixia]

oh well i tried.