CODEWITHSUNDEEP
c++visual-c++
vico
vico

Reputation: 18171

generating *char buffer

I need to create a buffer that contains 300 symbols and pass it to the function described below:

void printThis(char *info);

What is the best way to generate this buffer?

If this is good:

char *buffer = new char()

then, how to add characters to this buffer? The following method is not good and it raises an access violation:

for (int i=0; i<300;i++)
{
   sprintf(s,"%s",'a');
}

Upvotes: 0

Views: 253

Answers (2)

Puppy
Puppy

Reputation: 146910

if this is good:

It isn't. It really, really, isn't. It's not even a buffer. Nor is this even close to a good idea.

std::string s;
for(int i = 0; i < 300; i++)
    s.push_back('a'); // good job all round
std::cout << s; // 300*a. Why? Who knows?
printThis(s.c_str());

Upvotes: 0

Mike Seymour
Mike Seymour

Reputation: 254451

std::vector<char> buffer(300, 'a');

// I'm guessing that printThis wants a zero-terminated string
buffer.push_back(0);

printThis(&buffer[0]);

If you're using the C++11 library, then buffer.data() might look nicer than &buffer[0].

If you really want to manage the memory yourself (hint: you don't), either create an automatic array:

char buffer[300];

or a dynamic array:

char * buffer = new char[300];

// Don't forget to delete it, and hope than nothing threw an exception
delete [] buffer;

Upvotes: 4

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