Summary of common methods of string in STD

In programs, strings are often to be processed. In addition to the summary of some char methods previously written, strings are often used for string processing. The following is a summary of its common methods: 1. Definition: string & operator = (const string & s); // assign string s to the current string
String & assign (const char * s); // use the c-type string s to assign a value
String & assign (const char * s, int n); // assign values with n characters starting with string s
String & assign (const string & s); // assign string s to the current string
String & assign (int n, char c); // assign a value to the current string with n characters c
String & assign (const string & s, int start, int n); // assign the n characters starting from start in string s to the current string
String & assign (const_iterator first, const_itertor last); // assign the part between the first and last iterators to the string 2. append method: string & operator ++ = (const string & s); // connects string s to the end of the current string
String & append (const char * s); // connect string s of the c type to the end of the current string
String & append (const char * s, int n); // connect the first n characters of the c-type string s to the end of the current string
String & append (const string & s); // same as operator + = ()
String & append (const string & s, int pos, int n); // connects n characters starting from pos in string s to the end of the current string
String & append (int n, char c); // Add n characters to the end of the current string
String & append (const_iterator first, const_iterator last); // link the part of the iterator first and last to the end of the current string. 3. Compare the compar method: bool operator = (const string & s1, const string & s2) const; // compare whether two strings are equal
Operator ">", "<", "> =", "<= ","! = "Both are reloaded for string comparison;
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; // compare the size of s and the string consisting of n characters starting from pos of the current string
Int compare (int pos, int n, const string & s, int pos2, int n2) const; // compare the size of a string consisting of n characters starting from pos and n2 characters starting from pos2 in s
Int compare (const char * s) const;
Int compare (int pos, int n, const char * s) const;
Int compare (int pos, int n, const char * s, int pos2) const;
When the compare function is>, 1 is returned, <-1, = is returned, and 0 is returned. 4. find method: int find (char c, int pos = 0) const; // start from pos to find the position of character c in the current string
Int find (const char * s, int pos = 0) const; // start from pos to find the position of string s in the current string
Int find (const char * s, int pos, int n) const; // start from pos to find the position of the First n characters in string s in the current string
Int find (const string & s, int pos = 0) const; // search for the position of string s in the current string from pos
// Return the location when the search is successful. If the search fails, return the string: npos value.

Int rfind (char c, int pos = npos) const; // search for the position of character c in the current string from the pos to the forward
Int rfind (const char * s, int pos = npos) const;
Int rfind (const char * s, int pos, int n = npos) const;
Int rfind (const string & s, int pos = npos) const;
// Start from the pos and start from the back to the front to find the position of the string consisting of the First n characters in string s in the current string. If the string fails, return the value of string: npos.

Int find_first_of (char c, int pos = 0) const; // search for the position where character c appears for the first time from pos
Int find_first_of (const char * s, int pos = 0) const;
Int find_first_of (const char * s, int pos, int n) const;
Int find_first_of (const string & s, int pos = 0) const;
// Start from pos to find the position of the first character in the array consisting of the First n characters of s in the current string. String: npos

Int find_first_not_of (char c, int pos = 0) const;
Int find_first_not_of (const char * s, int pos = 0) const;
Int find_first_not_of (const char * s, int pos, int n) const;
Int find_first_not_of (const string & s, int pos = 0) const;
// Find the position of the first character not in the string s from the current string. If the string fails to appear, string: npos is returned.

Int find_last_of (char c, int pos = npos) const;
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;
// Find_last_of and find_last_not_of are similar to find_first_of and find_first_not_of, but they are searched from the back to the front. 5. insert the insert method: string & insert (int p0, const char * 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 );
// The first four functions Insert the first n characters starting with pos in the string s at the p0 position
String & insert (int p0, int n, char c); // This function inserts n characters in p0 c
Iterator insert (iterator it, char c); // insert character c in it to return the position of the iterator after insertion
Void insert (iterator it, const_iterator first, const_iterator last); // insert characters between [first, last) in it
Void insert (iterator it, int n, char c); // insert n characters in it c 6. Delete erase method: iterator erase (iterator first, iterator last ); // Delete All characters between [first, last) and return the position of the iterator after deletion
Iterator erase (iterator it); // deletes the characters it points to and returns the position of the iterator after deletion.
String & erase (int pos = 0, int n = npos); // Delete the n characters starting with pos, return the modified string 7. replace the replace method: string & replace (int p0, int n0, const char * s); // Delete the n0 characters starting with p0, and insert the string s at p0
String & replace (int p0, int n0, const char * s, int n); // Delete n0 characters starting with p0, insert the first n characters of string s in p0.
String & replace (int p0, int n0, const string & s); // Delete the n0 characters starting with p0, and insert the string s at p0
String & replace (int p0, int n0, const string & s, int pos, int n); // Delete n0 characters starting with p0, then insert n characters starting from pos in string s at p0
String & replace (int p0, int n0, int n, char c); // Delete n0 characters starting with p0, and then insert n characters c at p0
String & replace (iterator first0, iterator last0, const char * s); // replace the parts between [first0, last0) with the string s
String & replace (iterator first0, iterator last0, const char * s, int n); // replace the portion between [first0, last0) with the first n characters of s
String & replace (iterator first0, iterator last0, const string & s); // replace the parts between [first0, last0) with the string s
String & replace (iterator first0, iterator last0, int n, char c); // replace the parts between [first0, last0) with n characters c
String & replace (iterator first0, iterator last0, const_iterator first, const_iterator last); // replace the parts between [first0, last0) with strings between [first, last)
8. method for obtaining the string substr: string substr (int pos = 0, int n = npos) const; // return string 9 consisting of n characters starting with pos. swap switching method: void swap (string & s2); // exchange the value of the current string and s2