The wprintf() function is defined in <cwchar> header file.
wprintf() prototype
int wprintf( const wchar_t* format, ... );
The wprintf() function writes the wide string pointed to by format to stdout. The wide string format may contain format specifiers starting with % which are replaced by the values of variables that are passed to the wprintf() function as additional arguments.
wprintf() Parameters
- format: A pointer to a null terminated wide string that is written to stdout. It consists of wide characters along with optional format specifiers starting with %. The format specifiers are replaced by the values of respective variables that follows format.
The format specifier has the following parts:- A leading % sign
- Flags: Optional one or more flags that modifies the conversion behavior.
- - : Left justify the result within the field. By default it is right justified.
- + : The sign of the result is attached to the beginning of the value, even for positive results.
- Space: If there is no sign, a space is attached to the beginning of the result.
- # : An alternative form of the conversion is performed.
- 0 : It is used for integer and floating point number. Leading zeros are used to pad the numbers instead of space.
- Width: An optional * or integer value used to specify minimum width field.
- Precision : An optional field consisting of a . followed by * or integer or nothing to specify the precision.
- Length : An optional length modifier that specifies the size of the argument.
- Specifier: A conversion format specifier. The available format specifiers are as follows:
Format specifiers Format Specifier Description % Prints % c Writes a single character s Writes a character string d or i Converts a signed integer to decimal representation o Converts an unsigned integer to octal representation X or x Converts an unsigned integer to hexadecimal representation u Converts an unsigned integer to decimal representation F or f Converts floating-point number to the decimal representation E or e Converts floating-point number to the decimal exponent notation A or a Converts floating-point number to the hexadecimal exponent G or g Converts floating-point number to either decimal or decimal exponent notation n Returns the number of characters written so far by this call to the function. The result is written to the value pointed to by the argument p Writes an implementation defined character sequence defining a pointer.
So the general format of format specifier is:%[flags][width][.precision][length]specifier
- … : Other additional arguments specifying the data to be printed. They occur in a sequence according to the format specifier.
wprintf() Return value
- If successful, the wprintf() function returns number of characters written.
- On failure it returns a negative value.
Example: How wprintf() function works?
#include <cwchar>
#include <clocale>
int main()
{
wint_t x = 5;
wchar_t name[] = L"André ";
setlocale(LC_ALL, "en_US.UTF-8");
wprintf(L"x = %d \n", x);
wprintf(L"Hello %ls \n", name);
return 0;
}
When you run the program, the output will be:
x = 5 Hello André