Use of anonymous functions in go language

package main
import (
 "fmt"
 "go_code/chapter02/funinit/utils"
)
// 3. Global anonymous functionvar(
 Fun1 = func(n1 int,n2 int) int {
 return n1 * n2
  }
)
// init function, usually completes initialization work in init functionfunc main(){
 // 1. Call it directly when defining anonymous functions. This method can only be called once. res1 := func(n1 int,n2 int) int{
 return n1+n2
 }(10,20)
 ("res1=",res1)
 // 2. The data type of a is the function type. At this time, we can complete the call through a a := func(n1 int,n2 int) int{
 return n1 + n2
 }
 res2 := a(100,1000)
 ("res2=",res2)
 res3 := Fun1(100,1000)
 ("res3=",res3)
  ("main......")
  ("Age is value",,"Name is value",)
}

package main
import (
 "fmt"
)
func main() {
 func() {
   ("func 1\n")
 }()
 func(x int) {
   ("func 2, x is %d\n", x)
 }(2)
 a := func(x int) int {
   ("func 3, x is %d\n", x)
   return 5
   }
 (a(3))
 ("%T\n", func() {
   ("func 1\n")
 })
 ("%T\n", func(x int) {
   ("func 2, x is %d\n", x)
 })
 ("%T\n", a)
}

package main
import (
  "fmt"
)
func main() {
  test(func(x string) {
   (x)
 })
}
func test(f func(string)) {
  f("hello")
}

package main
import (
 "fmt"
)
func main() {
 func() {
   ("func 1\n")
 }
}
package main
import (
  "fmt"
)
func main() {
  test(func g(x string) {
   (x)
 })
}
func test(f func(string)) {
  f("hello")
}

package main
import (
  "fmt"
)
var x = "hello"
func main() {
  test(func (x *string) {
   *x = "world"
 })
 (x)
}
func test(f func(*string)) {
}
package main
import (
  "fmt"
)
func main() {
 var s1 = "hello"
 var s2 = "world"
  test(func(x *string, y *string) {
   *x += "_123"
   *y += "_456"
   }, &s1, &s2)
  (s1, s2) // hello_123 world_456
}
func test(f func(*string, *string), s1 *string, s2 *string) {
 f(s1, s2)
}
package main
import (
  "fmt"
)
var s1 = "hello"
var s2 = "world"
func main() {
  test(func(x *string, y *string) {
   *x += "_123"
   *y += "_456"
   })
  (s1, s2) // hello_123 world_456
}
func test(f func(*string, *string)) {
 f(&s1, &s2)
}