String formatting

Context

The fmt package provides powerful string formatting with verbs similar to C’s printf.

Common verbs:

%v – default format
%+v – struct with field names
%#v – Go syntax representation
%T – type
%d – integer (decimal)
%f – float
%s – string
%q – quoted string
%x – hexadecimal
%p – pointer

Example

Format various data types.

Code example

package main

import "fmt"

type Person struct {
    Name string
    Age  int
}

func main() {
    p := Person{"Alice", 30}
    fmt.Printf("Default: %v\n", p)
    fmt.Printf("+v: %+v\n", p)
    fmt.Printf("#v: %#v\n", p)
    fmt.Printf("Type: %T\n", p)

    n := 42
    f := 3.14159
    s := "hello"

    fmt.Printf("Int: %d, Hex: %x, Bin: %b\n", n, n, n)
    fmt.Printf("Float: %.2f\n", f)
    fmt.Printf("String: %s, Quoted: %q\n", s, s)
}

Output

Default: {Alice 30}
+v: {Name:Alice Age:30}
#v: main.Person{Name:"Alice", Age:30}
Type: main.Person
Int: 42, Hex: 2a, Bin: 101010
Float: 3.14
String: hello, Quoted: "hello"

String formatting

Context

Example

Code example

Output

Useful links