C Programming Tutorial
In the C Programming Language, the vfprintf function writes formatted output to stream using arg as the variable argument list.
Syntax
The syntax for the vfprintf function in the C Language is:
int vfprintf(FILE *stream, const char *format, va_list arg);
Parameters or Arguments
stream
The stream where the output will be written.
format
Describes the output as well as provides a placeholder to insert the formatted string. Here are a few examples:
| Format | Explanation | Example |
|---|---|---|
| %d | Display an integer | 10 |
| %f | Displays a floating-point number in fixed decimal format | 10.500000 |
| %.1f | Displays a floating-point number with 1 digit after the decimal | 10.5 |
| %e | Display a floating-point number in exponential (scientific notation) | 1.050000e+01 |
| %g | Display a floating-point number in either fixed decimal or exponential format depending on the size of the number (will not display trailing zeros) | 10.5 |
arg
A variable argument list.
Returns
The vfprintf function returns the number of characters that was written. If an error occurs, it will return a negative value.
Required Header
In the C Language, the required header for the vfprintf function is:
#include <stdio.h>
Applies To
In the C Language, the vfprintf function can be used in the following versions:
- ANSI/ISO 9899-1990
