fmt.Printf() 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.Printf() function in Go language formats according to a format specifier and writes to standard output. 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 Printf(format string, a ...interface{}) (n int, err error)

Parameters: This function accepts two parameters which are illustrated below: 

• format string: This contains some strings along with some verbs.
• a …interface{}: This contains specified constant variables.

Return Value: It returns the number of bytes written and any write error encountered.

Conversion Characters:

Conversion Characters	Description
%b	It is used to format base 2 numbers
%o	It is used to format base 8 numbers
%O	It is used to format base 8 numbers with 0o prefix
%d	It is used to format base 10 numbers with lower-case letters for a-f
%x	It is used to format base 16 numbers with upper-case letters for A-F
%X	It is used to format base 16 numbers
%g	It is used to format float values
%s	It is used to format string values
%t	It is used to format true or false values
%e	It is used to format scientific values

Example 1:

Go

// Golang program to illustrate the usage of
// fmt.Printf() function

// Including the main package
package main

// Importing fmt
import (
    "fmt"
)

// Calling main
func main() {

    // Declaring some const variables
    const name, dept = "GeeksforGeeks", "CS"

    // Calling Printf() function
    fmt.Printf("%s is a %s Portal.\n", name, dept)

    // It is conventional not to worry about any
    // error returned by Printf.

}

Output:

GeeksforGeeks is a CS portal.

Example 2:

Go

// Golang program to illustrate the usage of
// fmt.Printf() function

// Including the main package
package main

// Importing fmt
import (
    "fmt"
)

// Calling main
func main() {

    // Declaring some const variables
    const num1, num2, num3 = 5, 10, 15

    // Calling Printf() function
    fmt.Printf("%d + %d = %d\n", num1, num2, num3)

    // It is conventional not to worry about any
    // error returned by Printf.

}

Output:

5 + 10 = 15

Example 3:

Go

// Golang program to illustrate the usage of
// fmt.Printf() function

// Including the main package
package main

// Importing fmt
import (
    "fmt"
)

// Calling main
func main(){

    var str = "Geeksforgeeks"
      fmt.Printf("The string is %s \n", str)
    var num1 int = 21
      fmt.Printf("The decimal value is %d \n", num1)
    var num2 float32 = 7.786
      fmt.Printf("The floating point is %g \n", num2)
    var num3 int = 14
      fmt.Printf("The binary value of num3 is %b \n", num3)
    var num4 = 4 + 1i
    fmt.Printf("Scientific Notation of num4 : %e \n", num4)
}

Output:

The string is Geeksforgeeks  
The decimal value is 21  
The floating point is 7.786  
The binary value of num3 is 1110  
Scientific Notation of num4 : (4.000000e+00+1.000000e+00i)