This topic is about Go – function closure.
Go programming language supports anonymous functions which can acts as function closures. Anonymous functions are used when we want to define a function inline without passing any name to it.
In our example, we created a function getSequence() which returns another function. The purpose of this function is to close over a variable i of upper function to form a closure.
package main
import "fmt"
func getSequence() func() int {
i:=0
return func() int {
i+=1
return i
}
}
func main(){
/* nextNumber is now a function with i as 0 */
nextNumber := getSequence()
/* invoke nextNumber to increase i by 1 and return the same */
fmt.Println(nextNumber())
fmt.Println(nextNumber())
fmt.Println(nextNumber())
/* create a new sequence and see the result, i is 0 again*/
nextNumber1 := getSequence()
fmt.Println(nextNumber1())
fmt.Println(nextNumber1())
}
When the above code is compiled and executed, it produces the following result −
1 2 3 1 2
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