custom string exercise in c++

I have a custom string class that uses an array of chars,

class MyString
{

private:
int length; 
char *chars; 

public:
MyString(const char* input)
{
    length = 0; 
    while (input[length] != '\0')
        ++length;

    chars = new char[length + 1];

    for (int j = 0; j < length; j++)
        chars[j] = input[j];
}  

However when I use this class with a simple output I am getting a strange result in the console:

MyString newStr = "Test";
cout << newStr; 

Gives m开发者_运维知识库e this output in the console:

Test═²²²²½½½½½½½½■ε■ε■ε■

This is with Visual Studio 2010 Win32 console app. I don't really know c++ very well and this is my first try at it.

You forgot to put \0 at the end of chars[]. \0 is the character that MUST be put at the end of a char sequence. Otherwise, your program will output some random stuff (the bits after your array in memory) until it finds a \0.

Your loop that copies input to chars isn't including the NUL terminator. Change the loop condition to j <= length and it should work.

There are a couple of things that I'd recommend:

1. You are not null terminating your chars[]
2. you need to overload the << operator. Go to: http://www.fredosaurus.com/notes-cpp/oop-friends/overload-io.html for an example.