Go Formatting Verbs:
Formatting verbs in Go are special symbols used in functions like fmt.Printf to format variables. They start with a percent sign (%) and are followed by a character that determines how the value is formatted.
1. Common Verbs
%v— Default format%+v— Adds field names for structs%#v— Go-syntax representation%T— Type of the value
go
package main
import "fmt"
type Person struct { Name string; Age int }
func main() {
p := Person{Name: "John", Age: 30}
fmt.Printf("%v\n", p)
fmt.Printf("%+v\n", p)
fmt.Printf("%#v\n", p)
fmt.Printf("%T\n", p)
}2. Integer Verbs
%d— Decimal%b— Binary%o— Octal%x— Hex (lowercase)%X— Hex (uppercase)
go
package main
import "fmt"
func main() {
n := 42
fmt.Printf("Decimal: %d\n", n)
fmt.Printf("Binary: %b\n", n)
fmt.Printf("Octal: %o\n", n)
fmt.Printf("Hex: %x\n", n)
fmt.Printf("HEX: %X\n", n)
}3. Floating-Point Verbs
%f— Decimal point but no exponent%e— Scientific notation (e.g., -1.234456e+78)%E— Scientific notation with E
go
package main
import "fmt"
func main() {
pi := 3.1415926535
fmt.Printf("Float: %f\n", pi)
fmt.Printf("Scientific (e): %e\n", pi)
fmt.Printf("Scientific (E): %E\n", pi)
}4. String and Boolean Verbs
%s— String%q— Double-quoted string%t— Boolean
go
package main
import "fmt"
func main() {
str := "GoLang"
flag := true
fmt.Printf("String: %s\n", str)
fmt.Printf("Quoted: %q\n", str)
fmt.Printf("Boolean: %t\n", flag)
}Summary
Formatting verbs give you fine control over how output is displayed in Go. They are essential for logging, debugging, and structured output formatting.
