vector<unsigned char*> question

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?

Code:

---

#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.

Quote:

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Originally Posted by ekhule

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

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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.

Quote:

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Originally Posted by 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?

---

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

Code:

---

#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

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

vector<unsigned char*>&

parameter to a function

Quote:

---

Originally Posted by ekhule

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:

Code:

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

---

Regards,

Paul McKenzie

Quote:

---

Originally Posted by ekhule

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

vector<unsigned char*>&

parameter to a function

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