Closures

Context

Go functions can be anonymous and can form closures. A closure is a function value that references variables from outside its body. It captures those variables and can use them even after the outer function has returned.

Example

Create a closure that returns a function that increments a counter.

Code example

package main

import "fmt"

func counter() func() int {
    count := 0
    return func() int {
        count++
        return count
    }
}

func main() {
    inc := counter()
    fmt.Println(inc())
    fmt.Println(inc())
    fmt.Println(inc())

    another := counter()
    fmt.Println(another())
}

Output

1
2
3
1

Useful links

• Go by Example: Closures
• Go spec: Function literals