string container

container: string
head File: #include<string>

string is essentially a class, which is encapsulated inside the class char*, and all strings are char*containers of a type.

string constructor

constructor prototype

string();//Create an empty string such as: string str (no parameter constructor)

string(const char* s);//Initialize with string s (constructor with parameters)
string(const string& str);//Use a string object to initialize another string object (copy constructor)
string(int n,char c);//Initialize with n characters c (constructor with parameters)

The function prototype of the assignment:

string& operator = (const char* s); //char * type string is assigned to the current string
string& operator = (const string &s);//Assign the string s to the current string
string& operator = (char c);//Character assignment to the current string
string& assign(const char *s);//Assign the string s to the current string
string& assign(const char *s, int n);//Assign the first n characters of the string s to the current string
string& assign(const string &s);//Assign the string s to the current string
string& assign(int n, char c);// Assign n characters c to the current string

function prototype

string& operator+=(const char* str);// Overload += operator
string& operator+=(const char c);// Overload += operator
string& operator+=(const string& str);// Overload += operator
string& append(const char* s);//Connect the string s to the end of the current string
string& append(const char* str, int n); //同operator+=(const string& str)
string& append(const string& s);//同operator+=(const string& str)
string& append(const string& s, int pos, int n);//The n characters starting from pos in the string s are connected to the end of the string

function prototype

int find(const string& str, int pos = 0) const;//Find the first occurrence of str, starting from pos
int find(const char* s, int pos = 0) const;//Find the first occurrence of s, starting from pos
int find(const char* s, int pos, int n) const;//Find the first position of the first n characters of s from pos position
int find(const char c, int pos = 0) const;//Find the first occurrence of character c
int rfind(const string& str, int pos = npos) const;//Find the last position of str, starting from pos
int rfind(const char* s, int pos = posn) const;//Find the last occurrence of s, starting from pos
int rfind(const char* s, int pos, int n) const;//Find the last position of the first n characters of s from pos
int rfind(const char c,int pos = 0) const;//Find the last occurrence of character c
string& replace(int pos, int n, const string& str);//Replace n characters starting from pos with the string str
string& replace(int pos, int n, const char* s);//Replace the n characters starting from pos with the string s

=return 0
>return 1
<return -1

function prototype

There are two ways to access a single character in string

function prototype

string& insert(int pos, const char* s);//insert string
string& insert(int pos, const string& str);//insert string
string& insert(int pos, int n, char c);//Insert n characters c at the specified position
string& erase(int pos, int n = npos);//Delete n characters starting from pos

Functional description

function prototype

string substr(int pos = 0, int n = npos) const;//Returns a string consisting of n characters starting from pos