vector<unsigned char*> question

[ekhule]

Hello,

I have the following code that prints out only the first char of each string. Why does it not print out the entire unsgined char* ? How can I fix it so that it does?

#include <iostream>
#include <vector>
using namespace std;

void PrintVector(vector<unsigned char*>& data)
{
	for(size_t i = 0; i < data.size(); i++)
	{
		cout << *(data[i]) << endl;
	}
}

int main()
{
	vector<unsigned char*> testData;
	testData.push_back((unsigned char*)"12345678");
	testData.push_back((unsigned char*)"AAAAAAAAA");
	PrintVector(testData);
}

Regards,
Ellay K.

[Lindley]

Why does it not print out the entire unsgined char* ?

You are dereferencing the pointer, so the type going to cout is unsigned char, not unsigned char*.

If you don't dereference, then cout will probably print the address held by the pointer rather than the string as you want. I'm not positive though. This is because C usually stores strings in signed char arrays rather than unsigned, so the compiler may not have the "special case" logic in place which tells it to treat unsigned char*s as NULL-terminated strings. If you cast the unsigned char* to char*, it should work.

Of course, the simplest thing to do would be to avoid C-style strings entirely and use a vector<string> instead.

[Paul McKenzie]

Hello,

I have the following code that prints out only the first char of each string. Why does it not print out the entire unsgined char* ? How can I fix it so that it does?

Let me ask you -- is your goal to store strings in a vector? If it is, then store strings, not pointers.

#include <vector>
#include <string>
#include <iostream>

typedef std::vector<std::string> StringVector;

using namespace std;

void PrintVector(StringVector& data)
{
    for(size_t i = 0; i < data.size(); i++)
        cout << data[i] << endl;
}

int main()
{
    StringVector testData;
    testData.push_back("12345678");
    testData.push_back("AAAAAAAAA");
    PrintVector(testData);
}

Regards,

Paul McKenzie

[ekhule]

It is actually to store binary data.. I am using a library that takes in a:

vector<unsigned char*>&

parameter to a function

[Paul McKenzie]

It is actually to store binary data.. I am using a library that takes in a:

vector<unsigned char*>&

parameter to a function

A std::string can store binary data. Even this works:

typedef vector<unsigned char> BinaryBuffer;
vector<BinaryBuffer>&

Regards,

Paul McKenzie

[Lindley]

It is actually to store binary data.. I am using a library that takes in a:

vector<unsigned char*>&

parameter to a function

A bizarre choice. Does the library give a justification for this?