char *到std :: string

Question

I have a Character Array (char* pData) in C++, what i want to do is to copy some data (from pData) in std::string. The code looks like this:

std::string sSomeData(pData+8);//I want to copy all data starting from index 8 till end

The problem is that when above statement executes the string contains nothing in it. I guess that my pData is not terminated with '\\0' thats why its not working.

Regards, Jame.

Answer 1

如果您知道pData的大小，则可以使用construct-from-iterators构造函数：

std::string sSomeData(pData + 8, pData + size_of_pData);

Answer 2

If you don't know whether your data is NULL terminated or not then you should know the size of the data (ie how many characters are there). Otherwise there is no way to copy it. When you know the size, you can specify it in the string constructor. Following is a sample code:

int main( void )
{
    char p[] = {'N','a','v','e','e','n'};
    std::string s(p+3, p+6);
    return 0;
}

Answer 3

使用std::string sSomeData(pData+8, pData+8+n)其中n是要复制的字符数。