fmt.Fprintf() Function in Golang With Examples Last Updated : 28 Apr, 2025 Comments Improve Suggest changes Like Article Like Report In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fprintf() function in Go language formats according to a format specifier and writes to w. Moreover, this function is defined under the fmt package. Here, you need to import the "fmt" package in order to use these functions. Syntax: func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) Parameters: This function accepts three parameters which are illustrated below- w io.Writer: This is the specified standard input or output.format string: This is containing some strings including verbs.a ...interface{}: This is the specified constant variables used in the code. Return Value: It returns the number of bytes written and any write error encountered.Example 1: C // Golang program to illustrate the usage of // fmt.Fprintf() function // Including the main package package main // Importing fmt and os import ( "fmt" "os" ) // Calling main func main() { // Declaring some const variables const name, dept = "GeeksforGeeks", "CS" // Calling Fprintf() function which returns // "n" as the number of bytes written and // "err" as any error ancountered n, err := fmt.Fprintf(os.Stdout, "%s is a %s portal.\n", name, dept) // Printing the number of bytes written fmt.Print(n, " bytes written.\n") // Printing if any error encountered fmt.Print(err) } Output: GeeksforGeeks is a CS portal. 30 bytes written. <nil> Example 2: C // Golang program to illustrate the usage of // fmt.Fprintf() function // Including the main package package main // Importing fmt and os import ( "fmt" "os" ) // Calling main func main() { // Declaring some const variables const num1, num2, num3 = 5, 10, 15 // Calling Fprintf() function which returns // "n" as the number of bytes written and // "err" as any error encountered n, err := fmt.Fprintf(os.Stdout, "%d + %d = %d.\n", num1, num2, num3) // Printing the number of bytes written fmt.Print(n, " bytes written.\n") // Printing if any error encountered fmt.Print(err) } Output: 5 + 10 = 15. 13 bytes written. <nil> Comment More infoAdvertise with us Next Article fmt.Fprintf() Function in Golang With Examples K Kanchan_Ray Follow Improve Article Tags : Go Language Golang-fmt Similar Reads fmt.Fprint() Function in Golang With Examples In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fprint() function in Go language formats using the default formats for its operands and writes to w. Here Spaces are added between operands when any string is not used as a par 3 min read fmt.Fprintln() Function in Golang With Examples In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fprintln() function in Go language formats using the default formats for its operands and writes to w. Here Spaces are always added between the specified operands and a newline 3 min read fmt.Fscanf() Function in Golang With Examples In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fscanf() function in Go language scans the specified text, read from r and then stores the successive space-separated values into successive arguments as determined by the form 3 min read fmt.Fscan() Function in Golang With Examples In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fscan() function in Go language scans the specified text, read from r, and then stores the successive space-separated values into successive arguments. Here newlines get counte 3 min read fmt.Fscanln() Function in Golang With Examples In Go language, fmt package implements formatted I/O with functions analogous to C's printf() and scanf() function. The fmt.Fscanln() function in Go language scans the specified text, read from r and then stores successive space-separated values into successive arguments. This function stops scannin 3 min read Like