Why do I get "0xC0000005: Access violation reading location 0x0000000000000000"

So in one getter method I’m simply trying to get the length of a c-style string (c-style strings give me headaches) and it works everywhere else in the code except on 1 line stated below the code

#include <iostream>
#include <cstring>
#pragma warning(disable : 4996)

using namespace std;

class MyString
{
private:
    char *str;
public:
    int get_length() const { return strlen(str); }
    char get_string() const { return *str; }
    void display_obj() const
    {
        cout << str << " : " << get_length() << endl;
    }
    MyString()
        :str{nullptr}
    {
        str = new char[1];
        str = '\0';
    }
    MyString(const char *s)
        :str{nullptr}
    {
        str = new char[strlen(s) + 1];
        strcpy(str, s);
    }
    MyString(const MyString &source)
        :str{ nullptr }
    {
        str = new char[strlen(source.str) + 1];
        strcpy(str, source.str);
    }
    MyString(MyString &&source)
        :str{ source.str }
    {
        source.str = nullptr;
    }
    MyString &MyString::operator=(const MyString &source)
    {
        if (this == &source)
            return *this;
        delete[] str;
        str = new char[strlen(source.str) + 1];
        strcpy(str, source.str);
        return *this;
    }
    MyString &MyString::operator=(MyString &&source)
    {
        if (this == &source)
            return *this;
        delete[] str;
        str = source.str;
        source.str = nullptr;
        return *this;
    }
    ~MyString() { delete str; }
};

int main()
{
    MyString a{ "hello" };
    MyString b;
    b.display_obj();
    b = a;
    b.display_obj();
    b = "Tatarusanu";
    b.display_obj();
    system("pause");
    return 0;
}

and here

int get_length() const { return strlen(str); }

I get thrown the exception "Exception thrown at 0x00007FF98602F621 (ucrtbased.dll) in Project1.exe: 0xC0000005: Access violation reading location 0x0000000000000000" and I have no idea why. Any suggestions?

>Solution :

MyString()
    :str{nullptr}
{
    str = new char[1];
    //str = '\0'; // <-- here is your mistake
    str[0] = '\0'; // do this instead
}