c++编程之字符和字符串

#include <iostream>

int main(int argc, char *argv[]) {
	char *str1 = "hello";
	// warning: deprecated conversion from string constant to 'char *';
	char *str2 = const_cast<char *>("hello"); // remove the "const"

	const char *str3 = "hello";
	// *(str3 + 1) = 'a'; // error: assignment of read-only location '*(str3 + 1)'

	char str4[] = "hello";
	str4[1] = 'a';
	const char str5[] = "hello";
	//str5[1] = 'a' // error: assignment of read-only location 'str5[1]
	return 0;
}

inline void strtoupper(char *str) {
	while (*str) {
		*str = toupper(*str);
		++str;
	}
}

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

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

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

// Capacity
size_t size () const;    // Return the size of the string
size_t length () const;  // same as above
                         // length() was from earlier version, size() added for compatibility with STL
bool empty () const;     // Return true for empty string
void clear ();           // Clear to empty string
void resize (size_t n, char pad = '\0');  // resize the string to length n,
                                          // discard trailing characters, or insert pad char

string::npos             // static variable for the maximum possible characters in string,
                         // typically max of size_t (unsigned int)
size_t max_size () const;    // Return the maximum size of string object
size_t capacity () const;    // Storage (in terms of characters) currently allocated
void reserve (size_t n = 0); // Request for minimum of this capacity
void shrink_to_fit ();