Suppose a String class has the following private members:
class String
{
private:
char * str; // points to string allocated by new
int len; // holds length of string
//...
};

a. What’s wrong with this default constructor?
String::String() {}
b. What’s wrong with this constructor?
String::String(const char * s)
{
str = s;
len = strlen(s);
}
c. What’s wrong with this constructor?
String::String(const char * s)
{
strcpy(str, s);
len = strlen(s);
}