Conversion of C + + int to string

Transferred from: http://www.cnblogs.com/nzbbody/p/3504199.html

the int itself is represented by a string of characters, with no double quotes, and tells the compiler to interpret it as a number. By default, it is interpreted as 10-binary (dec), if you want to use 8 binary, 16 binary, what should I do? Add a prefix that tells the compiler to interpret it according to the different binary. 8 binary (OCT)---prefix plus 0,16 (hex)---prefix plus 0x or 0X.

The string is preceded by a double quotation mark that tells the compiler to interpret it as a string of characters.

Note: For characters, you need to differentiate between characters and the numeric value represented by a character. For example: char a = 8;char B = ' 8 ', a for the 8th character, b for the character 8, and the 56th character.

convert int to string

1. Using itoa (int to string)

1  //char *itoa (int value, char *string,int radix), 2  //Prototype Description: 3  //value: data to be converted. 4  //string: The address of the target string. 5  //radix: The converted binary number, can be 10, 16 and so on. 6  //Returns a pointer to string that is 7  8  int aa = 9  char c[8];10  itoa (aa,c,16);  cout<<c< <endl; 1e

Note: Itoa is not a standard C function, it is unique to Windows, if you want to write a cross-platform program, please use sprintf.

2. Using sprintf

1  //int sprintf (char *buffer, const char *format, [argument] ...); 2  //Parameter list 3  //Buffer:char pointer, pointing to the character to be written string of buffers. 4  //format: formatted string. 5  //[argument] ... : optional parameter, which can be any type of data. 6  //return value: String Length (strlen) 7  8  int aa = 9  char c[8];  int length = sprintf (c, "%05x", aa); 11
   cout<<c<<endl; 0001E

3. Using StringStream

1  int aa = 30;2  stringstream ss;3  ss<<aa; 4  string s1 = Ss.str (); 5  cout<<s1<< Endl 306 7  String s2;8  ss>>s2;9  cout<<s2<<endl;//30

It can be understood that stringstream can swallow different types, depending on the type of S2, and then spit out the different types.
4. Using the Lexical_cast in the Boost library

1  int aa = 30;2  string s = boost::lexical_cast<string> (AA); 3  cout<<s<<endl;//30

3 and 4 can only be converted to a 10 binary string, and cannot be converted to another binary string.

Convert String to int
1. Using Strtol (string to Long)

1 string s = "n"; 2  char* end;3  int i = static_cast<int> (Strtol (S.c_str (), &end,16)); 4  cout <<i<<endl; 235 6  i = static_cast<int> (Strtol (S.c_str (), &end,10)); 7  cout<<i<<endl;//17

2. Using sscanf

1 int i;2  sscanf ("n", "%d", &i), 3  cout<<i<<endl;//174 5  sscanf ("n", "%x", &i); 6  cout<<i<<endl;//237 8  sscanf ("0X17", "%x", &i); 9  cout<<i<<endl;//23

3. Using StringStream

1  string s = "n"; 2 3  stringstream ss;4  ss<<s;5 6  int i;7  ss>>i;8  cout< <i<<endl; 17

Note: StringStream can swallow any type and spit out different types according to actual needs.
4. Using the Lexical_cast in the Boost library

1  string s = "n"; 2  int i = boost::lexical_cast<int> (s); 3  cout<<i<<endl;//17

Conversion of C + + int to string