After programming a little in C I decided to jump right into C++. At first I was pleased with the presence of the string class and being able to treat strings as whole units instead of arrays of characters. But I soon found that the C-style strings had the advantage of letting the program move through it character by character, using pointer arithmetic, and carry out a desired logical operation.
I have now found myself in a situation that requires this but the compiler tells me it is unable to convert from type string to the C-style strings. So I was wondering, is there a way to use pointer arithmetic to reference single characters or to pass arguments to a function as the address of the first character while still using the string class without having to create arrays of characters or do I just want to have my cake and eat it too?
string characters can be accessed by index, pointers, and through the use of iterators.
if you wanted to use iterators, you could make a function that checks whether a string has a space in it or not:
bool spacecheck(const string& s)
{
string::const_iterator iter = s.begin();
while(iter != s.end()){
if (isspace(*iter))
return true;
else
++iter;
}
}
At the beginning of the function, I initialized an iterator to the beginning of the string s by using the .begin() function, which in this case returns an iterator to the first character in a string. In the while function, the condition is that iter != s.end(). In this case end() returns in iterator referring to the element after the last character of the string. In the body, (*iter), which is the value pointed to by iter, is sent to the function isspace(), which checks if a character is a space. If it fails, iter is incremented, which makes iter point to the next element of the string.
I am learning c++ myself and by writing all of this stuff out it has helped my own understanding some. I hope I did not offend you if this all seemed very simple to you, I was just trying to be concise.
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