Book says that "theString.clear();" is in <string> Compiler says no. What can I do?

Hi,

My first time here.

I have a very old degee in CPS and am taking a C++ class and I want to clear my string. I don't want to
thestring = ' ';
because I want to concatenate other strings on to this. I want the string to be totally empty.

My textbook says that there are a ton of member functions to work with strings. one of them is:
theString.clear();
The book says it is in <string>. But when I go to compile I get this error message:
E:\SUSAN\C++\Lab4.cpp(57) : error C2039: 'clear' : is not a member of 'basic_string<char,struct std::char_traits<char>,class std::allocator<char> >'

Can someone here please tell me what this means?
I looked at all the .h files on my computer and I don't see any other ones to do string manipulation. I read the .h file and I did not see any mention of the ".clear()" function.

I am most grateful.

Susan

Try

std::string whatever = "";

Such will be essentially blank... there is no leading space. It will be fine for concatation.

whatever+= "Hello ";
whatever+= "World";

will output cause the string to contain "Hello World", as expected.

Use erase() instead of clear() .

I don't know where your book took it, but in STL, the efficient way to clear a string is theString.erase();

Dear Shmulik,

Ya, hoo.
theString.erase(); worked perfect. I think that using.erase() is more explicit than just setting the string = to a null quote.

Thank you. I also wonder where clear() came from in my textbook?

You know how the little window pops up when you type a
dot after a variable, well clear was not one of my options but erase was on the list.

I see you are new here, as I am, and I really appreciate the time you took to respond.

Thanks,
Susan