C + + Learning: string usage

Function	Function prototypes	Description
constructor function	String (const char *s);	Class with C-style string S.
	string (int N,char c);	Initialize with n characters c
		Default constructor
		Copy constructor
accessing elements	const char &operator[] (int n) const;	Operator[] and at () both return the position of the nth character in the current string, but the at function provides a scope check that throws a Out_of_range exception when it crosses the border, and the subscript operator [] does not provide check access.
	Char &operator[] (int n);
	const char &at (int n) const;
	char &at (int n);
C-style string manipulation	const char *data () const;	Returns a non-null-terminated C-character array
	const char *C_STR () const;	Returns a null-terminated C string
	int copy (char *s, int n, int pos = 0) const;	Copies the n characters starting at Pos in the current string to a character array starting with S, returning the number of actual copies
Feature description	int capacity () const;	Returns the current capacity (that is, the number of elements in a string that do not have to increase memory)
	int max_size () const;	Returns the length of the largest string that can be stored in a string object
	int size () const;	Returns the size of the current string
	int length () const;	Returns the length of the current string
	BOOL empty () const;	Whether the current string is empty
	void Resize (int len,char c);	Set the current size of the string to Len and fill in the insufficient portion with the character C
Input/Output	Overloaded operator operator>>	For input
	Overloaded operator operator<<	For output
	Getline (IStream &in,string &s);	Used to read the string from the input stream in to s, separated by the newline character ' \ n '.
Assign value	String &operator= (const string &s);	Assigns the string s to the current string
	String &assign (const char *s);	Assign a value to the C type string s
	String &assign (const char *s,int n);	n characters assigned value starting with C string s
	String &assign (const string &s);	Assigns the string s to the current string
	String &assign (int n,char c);	Assigns a value to the current string with n characters c
	String &assign (const string &s,int start,int N);	Assigned n characters from start in string s to the current string
	String &assign (Const_iterator first,const_itertor last);	Assigns the part between first and last iterators to a string
Connection	String &operator+= (const string &s);	Concatenate the string s to the end of the current string
	String &append (const char *s);	Concatenate the C-type string s to the end of the current string
	String &append (const char *s,int n);	Connect prompt the first n characters of type C string s to the end of the current string
	String &append (const string &s);	With operator+= ()
	String &append (const string &s,int pos,int N);	Connect prompt the n characters from the POS in the string s to the end of the current string
	String &append (int n,char c);	Adds n characters to the end of the current string C
	String &append (Const_iterator first,const_iterator last);	Connect the part between the iterator first and last to the end of the current string
Comparison	BOOL operator== (const string &s1,const string &s2) const;	Compare two strings for equality, operator ">", "<", ">=", "<=", "! =" are overloaded for string comparisons
	int compare (const string &s) const;	Compare the size of the current string and s
	int compare (int pos, int n,const string &s) const;	Compares the size of a string of n characters starting with the current string from POS to s
	int compare (int pos, int n,const string &s,int pos2,int n2) const;	Compares the size of a string of n characters starting at the beginning of the current string from Pos with N2 characters starting with Pos2 in S
	int compare (const char *s) const;	Compared to a C-style string. The Compare function returns -1,== when > returns 1,< when return is 0
	int compare (int pos, int n,const char *s) const;
	int compare (int pos, int n,const char *s, int pos2) const;
Sub-string	String substr (int pos = 0,int n = npos) const;	Returns a string of n characters starting at Pos
Exchange	void Swap (string &s2);	Swap the current string with the value of S2
Find	int find (char c, int pos = 0) const;	Finds the character C from the Pos at the position of the current string, returns the location when the lookup succeeds, and fails to return the value of String::npos
	int find (const char *s, int pos = 0) const;	Finds the position of the string s in the current string starting from the POS, returns the location when the lookup succeeds, and fails to return the value of String::npos
	int find (const char *s, int pos, int n) const;	Finds the position of the first n characters of the string s in the current string from the point of POS, returns the location when the lookup succeeds, and fails to return the value of String::npos
	int find (const string &s, int pos = 0) const;	Finds the position of the string s in the current string starting from the POS, returns the location when the lookup succeeds, and fails to return the value of String::npos
	int RFind (char c, int pos = NPOs) const;	The position of the character C in the current string, starting from the POS and looking forward from behind
	int rfind (const char *s, int pos = NPOs) const;	Returns the position of the string s in the current string from the start of the POS, back to the position where it was successfully returned, returning the value of String::npos on failure
	int rfind (const char *s, int pos = NPOs, int n) const;	Finds the position of the first n characters in the string s in the current string from the beginning of the POS, and returns the value of String::npos on failure.
	int RFind (const string &s,int pos = NPOs) const;	Returns the position of the string s in the current string from the start of the POS, back to the position where it was successfully returned, returning the value of String::npos on failure
	int find_first_of (char c, int pos = 0) const;	Find the first occurrence of the character C starting from Pos
	int find_first_of (const char *s, int pos = 0) const;	Finds the position of the first s in the current string, starting from the Pos. Find failed return String::npos
	int find_first_of (const char *s, int pos, int n) const;	Finds the position of the character in the first n-character array of s in the current string starting from Pos. Find failed return String::npos
	int find_first_of (const string &s,int pos = 0) const;	Finds the position of the first s in the current string, starting from the Pos. Find failed return String::npos
	int find_first_not_of (char c, int pos = 0) const;	Finds the first position not appearing in the current string where the character C appears from the POS, and fails back to String::npos
	int find_first_not_of (const char *s, int pos = 0) const;	Finds the first position in the string s that does not appear in the current string, starting with the POS, and fails back to String::npos
	int find_first_not_of (const char *s, int pos,int n) const;	Finds the position of the first n-character string that does not appear in the current string, starting from the POS, and fails back to String::npos
	int find_first_not_of (const string &s,int pos = 0) const;	Finds the first position in the string s that does not appear in the current string, starting with the POS, and fails back to String::npos
	int find_last_of (char c, int pos = NPOs) const;	Find_last_of and find_last_not_of are similar to find_first_of and find_first_not_of, except that they look forward from behind.
	int find_last_of (const char *s, int pos = NPOs) const;
	int find_last_of (const char *s, int pos, int n = npos) const;
	int find_last_of (const string &s,int pos = NPOs) const;
	int find_last_not_of (char c, int pos = NPOs) const;
	int find_last_not_of (const char *s, int pos = NPOs) const;
	int find_last_not_of (const char *s, int pos, int n) const;
	int find_last_not_of (const string &s,int pos = NPOs) const;
Replace	String &replace (int p0, int n0,const char *s);	Delete N0 characters starting with P0 and insert string s at P0
	String &replace (int p0, int n0,const char *s, int n);	Remove N0 characters starting with P0, and then insert the first n characters of the string s at P0
	String &replace (int p0, int n0,const string &s);	Delete N0 characters starting with P0 and insert string s at P0
	String &replace (int p0, int n0,const string &s, int pos, int n);	Delete N0 characters starting with P0 and then insert string s n characters from Pos at P0
	String &replace (int p0, int n0,int n, char c);	Remove N0 characters starting with P0, and then insert n characters at P0 c
	String &replace (iterator first0, iterator last0,const char *s);	Replace the section between [First0,last0] with the string s
	String &replace (iterator first0, iterator last0,const char *s, int n);	Replace the section between [First0,last0] with the first n characters of S
	String &replace (iterator first0, iterator last0,const string &s);	Replace the section between [First0,last0] with a string s
	String &replace (iterator first0, iterator last0,int N, char c);	Replace the section between [First0,last0] with n characters c
	String &replace (iterator first0, iterator Last0,const_iterator first, const_iterator last);	Replace the part between [First0,last0] with a string between [First,last]
Insert	String &insert (int p0, const char *s);	Inserts the first n characters of the POS starting in the P0 position in the string s
	String &insert (int p0, const char *s, int n);
	String &insert (int p0,const string &s);
	String &insert (int p0,const string &s, int pos, int n);
	String &insert (int p0, int n, char c);	This function inserts n characters c at p0
	Iterator insert (iterator it, char c);	Insert character C at it to return the position of the post-insertion iterator
	void Insert (iterator it, Const_iterator first, const_iterator last);	Insert the characters between [First,last] in the IT department
	void Insert (iterator it, int n, char c);	Insert n characters c in it
Delete	string& Erase (size_t pos = 0, size_t n = NPOs);	Delete n characters starting from POS, return modified string
	Iterator Erase (iterator it);	Remove the character that it points to, and return the location of the post-delete iterator
	Iterator Erase (iterator first, iterator last);	Delete the characters from first to last (both first and last are iterators), returning the position of the post-delete iterator
Iterators	Const_iterator begin () const;	Returns the starting position of the string. To declare an iterator variable with string::iterator or String::const_iterator, Const_iterator does not allow the content of the iteration to be changed
	Iterator begin ();
	Const_iterator end () const;	Returns the position after the last character of a string
	Iterator End ();
	Const_iterator rbegin () const;	Returns the position of the last character of a string. Rbegin and rend are used for iterative access from backward forward, by setting the iterator String::reverse_iterator,string::const_reverse_iterator implementation
	Iterator Rbegin ();
	Const_iterator rend () const;	Returns the position in front of the first character of a string
	Iterator rend ();
Stream processing		By defining Ostringstream and Istringstream variable implementations, #include <sstream> header files

C + + Learning: string usage