Printing out the hex vale of an unsigned char array in C++ - c++

Question

I want to print out the hex value of an unsigned char array using the cout function.
The most obvious approach would be something like the following.
unsigned char str[] = "foo bar baz\n";
for(unsigned short int i = 0; i < sizeof(str); i++){
std::cout << std::hex << str[i] << std::dec << ' ';
}
std::cout << std::endl;
Suprisingly, this outputs the following string:
foo bar baz
For some reason this does not print out the proper hexadecimal value of str
How can I cout the proper hex value of str?

Answer 1

To cout the proper hex value of an unsigned char, it will need to be converted to an integer first.
unsigned char str[] = "foo bar baz\n";
for(unsigned short int i = 0; i < sizeof(str); i++){
std::cout << std::hex << (int) str[i] << std::dec << ' ';
}
std::cout << std::endl;
Gives the following output.
66 6f 6f 20 62 61 72 20 62 61 7a 00
Which corresponds with the hex value of each unsigned char in str.
An explaination for this can be found in the following std::hex documentation.
std::hex
Sets the basefield format flag for the str stream to hex.
When basefield is set to hex, integer values inserted into the stream are expressed in hexadecimal base (i.e., radix 16). For input streams, extracted values are also expected to be expressed in hexadecimal base when this flag is set.
http://www.cplusplus.com/reference/ios/hex/