Go language: defer the function execution

‘defer’ statement is used to defer the execution of a function until the surrounding function returns.

Syntax

defer function

App.go

package main

import "fmt"

func main() {

 defer fmt.Println(", Welcome to Go Language")

 defer fmt.Print("Hello ")
}

Output

Hello , Welcome to Go Language

When a function returns, deferred calls are executed in LIFO (Last-In-First-Out) order.

App.go

package main

import "fmt"

func main() {

 fmt.Println("Starting Execution")

 for i := 0; i < 10; i++ {
  defer fmt.Println(i)
 }
 defer fmt.Println("Finished Execution")
}

Output

Starting Execution

Finished Execution

9

8

7

6

5

4

3

2

1

0

Note

a.   defer statements are mainly used to clean the resources

b.   defer will be called, even if there is an error in the code.

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