Question

How to use anonymous functions (closure) in Go

Answer 1

package main

import (  
    "fmt"
)

func get_num() func() int {
    n := 0
    return func() int {
        n++
        return n
    }
}
func main() {  
     f := get_num()
	 
	 fmt.Println(f())
     fmt.Println(f())
     fmt.Println(f())
	 fmt.Println(f())
	 
	 f2 := get_num()
     fmt.Println(f2())
}
  
  
/*
run:
  
1
2
3
4
1
 
*/

 

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Answer 2

package main

import "fmt"

func add() func(int) int {
	sum := 0
	return func(n int) int {
		sum += n
		return sum
	}
}

func main() {
	a1, a2 := add(), add()
	for i := 0; i < 10; i++ {
		fmt.Println(a1(i), a2(i * 2))
	}
}


/*
run:

0 0
1 2
3 6
6 12
10 20
15 30
21 42
28 56
36 72
45 90

*/

 

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