Identifying characters in strings

What is the shortest way to check if a string contains the character "-" or it con开发者_如何转开发tains only numbers?

Edit: And how would I do it in C without std::string? Which one is better?

std::string has a member function, find, which can be used to search for a character or substring. It returns std::string::npos if the search character or substring is not found.

One straightforward way to test whether a string contains only digits is to use the find_first_not_of member function with the search list "0123456789". If it returns std::string::npos, the string contains only digits; if it returns any other value, there is some other, nondigit character in the string.

To check if it contains any character for eg. "-" you can use the strchr() c library call.

As to checking if a string contains only numbers you most probably have to iterate through all characters and check if it is a digit using isdigit() c library call.

As for the C++ way take a look at James McNellis's answer.

std::string myStr = "999-111-100";
if(myStr.find("-")!=std::string::npos)
{
    //string has a - in it
}