c++编程之字符和字符串

 1#include <iostream>
 2
 3int main(int argc, char *argv[]) {
 4	char *str1 = "hello";
 5	// warning: deprecated conversion from string constant to 'char *';
 6	char *str2 = const_cast<char *>("hello"); // remove the "const"
 7
 8	const char *str3 = "hello";
 9	// *(str3 + 1) = 'a'; // error: assignment of read-only location '*(str3 + 1)'
10
11	char str4[] = "hello";
12	str4[1] = 'a';
13	const char str5[] = "hello";
14	//str5[1] = 'a' // error: assignment of read-only location 'str5[1]
15	return 0;
16}

1inline void strtoupper(char *str) {
2	while (*str) {
3		*str = toupper(*str);
4		++str;
5	}
6}

1typedef basic_string<char> string;
2typedef basic_string<wchar_t> wstring;

 1string ();
 2   // (1) Default constructor: construct an empty string of length 0.
 3string (const string & str);
 4   // (2) Copy constructor: construct by copying str (by value)
 5string (const string & str, size_t pos, size_t len = npos);
 6   // (3) Substring constructor: copy the substring starting at pos, of the len.
 7   // size_t is usually typedef to unsigned int
 8   // npos is a static constant in string (i.e., string::npos),
 9   //   which holds the maximum value of size_t.
10string (const char * cstr);
11   // (4) C-string: construct by copying the C-string.
12string (const char * cstr, size_t len);
13   // (5) C-string buffer: construct by copying the cstr for len
14string (size_t len, char c);
15   // (6) Fill Constructor: fill len with char c
16template <class Iterator>
17string (Iterator first, Iterator last);
18   // (7) Iterator: copy the char in [first, last)
19string (initializer_list<char> initList);
20   // (C++11)(8) Initializer list
21string (string && str) noexcept;
22   // (C++11)(9) Move Constructor

1string str1("apple");
2string str2 = "orange";
3// '=' is not an assignment, but an implicit call to string's
4// constructor str2("orange");

 1// Capacity
 2size_t size () const;    // Return the size of the string
 3size_t length () const;  // same as above
 4                         // length() was from earlier version, size() added for compatibility with STL
 5bool empty () const;     // Return true for empty string
 6void clear ();           // Clear to empty string
 7void resize (size_t n, char pad = '\0');  // resize the string to length n,
 8                                          // discard trailing characters, or insert pad char
 9
10string::npos             // static variable for the maximum possible characters in string,
11                         // typically max of size_t (unsigned int)
12size_t max_size () const;    // Return the maximum size of string object
13size_t capacity () const;    // Storage (in terms of characters) currently allocated
14void reserve (size_t n = 0); // Request for minimum of this capacity
15void shrink_to_fit ();