package main
import (
"fmt"
"os"
)
type point struct {
x, y int
}
func main() {
p := point{1, 2}
fmt.Printf("struct1: %v\n", p)
fmt.Printf("struct2: %+v\n", p)
fmt.Printf("struct3: %#v\n", p)
fmt.Printf("type: %T\n", p)
fmt.Printf("bool: %t\n", true)
fmt.Printf("int: %d\n", 123)
fmt.Printf("bin: %b\n", 14)
fmt.Printf("char: %c\n", 33)
fmt.Printf("hex: %x\n", 456)
fmt.Printf("float1: %f\n", 78.9)
fmt.Printf("float2: %e\n", 123400000.0)
fmt.Printf("float3: %E\n", 123400000.0)
fmt.Printf("str1: %s\n", "\"string\"")
fmt.Printf("str2: %q\n", "\"string\"")
fmt.Printf("str3: %x\n", "hex this")
fmt.Printf("pointer: %p\n", &p)
fmt.Printf("width1: |%6d|%6d|\n", 12, 345)
fmt.Printf("width2: |%6.2f|%6.2f|\n", 1.2, 3.45)
fmt.Printf("width3: |%-6.2f|%-6.2f|\n", 1.2, 3.45)
fmt.Printf("width4: |%6s|%6s|\n", "foo", "b")
fmt.Printf("width5: |%-6s|%-6s|\n", "foo", "b")
s := fmt.Sprintf("sprintf: a %s", "string")
fmt.Println(s)
fmt.Fprintf(os.Stderr, "io: an %s\n", "error")
}$ go run string-formatting.go
struct1: {1 2}
struct2: {x:1 y:2}
struct3: main.point{x:1, y:2}
type: main.point
bool: true
int: 123
bin: 1110
char: !
hex: 1c8
float1: 78.900000
float2: 1.234000e+08
float3: 1.234000E+08
str1: "string"
str2: "\"string\""
str3: 6865782074686973
pointer: 0xc0000ba000
width1: | 12| 345|
width2: | 1.20| 3.45|
width3: |1.20 |3.45 |
width4: | foo| b|
width5: |foo |b |
sprintf: a string
io: an error