Implementation of class string constructors, copy constructors, destructors, and assignment functions

Class String class String {public:string (const char *STR = NULL);//constructor string (const string &other);//Copy Constructor ~s Tring (void); destructor string &operator = (const string &other); The assignment function Private:char *m_data;

Used to save the string};
		Constructor string::string (const char *str) {if (str = NULL)//judgment is null {m_data = new char[1];
	*m_data = ' n ';
		else {int len = strlen (str);
		m_data = new Char[len+1];
	strcpy (m_data, str); }//Copy constructor (must be used when constructing an object)//When the object is constructed, the object does not occupy memory at this time, without releasing string::string (const String &other) {int len = strlen (other.m_da
	TA);
	m_data = new Char[len+1];
strcpy (M_data, other.m_data); }//Assignment function (memory space occupied)//1. Before assigning a value, determine whether to assign value//2. Before assigning, the memory space is ready: The object already has a certain amount of memory before the assignment, but the size of the assigned object is not necessarily the same as the size of the object occupied//memory; Release the memory that the object already occupies.
The new memory is then allocated. String & string::operator = (const string &other) {if (&other = this)//to determine if self assignment {return this;} de lete []m_data;
	Frees object occupied memory int len = strlen (other.m_data); m_data = new Char[len+1];
	
Reallocate Memory strcpy (m_data, other.m_data);	return this;
 }//destructor string::~string () {delete []m_data;}