Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

package main

import (
    "fmt"
    "os"
)

// safeDiv recovers from a panic and returns an error instead.
func safeDiv(a, b int) (result int, err error) {
    defer func() {
        if r := recover(); r != nil {
            err = fmt.Errorf("recovered from panic: %v", r)
        }
    }()
    result = a / b // panics if b == 0
    return
}

// openFile shows defer for cleanup
func openFile(name string) error {
    f, err := os.Open(name)
    if err != nil {
        return err
    }
    defer f.Close() // guaranteed to run

// ... process file ...
    fmt.Println("opened:", f.Name())
    return nil
}

// deferOrder shows LIFO execution
func deferOrder() {
    for i := 0; i < 3; i++ {
        defer fmt.Printf("deferred %d
", i)
    }
    fmt.Println("after loop")
}

func main() {
    res, err := safeDiv(10, 2)
    fmt.Println("10/2 =", res, err)

res, err = safeDiv(10, 0)
    fmt.Println("10/0 =", res, err)

_ = openFile("nonexistent.txt")

deferOrder()
    // prints: after loop, deferred 2, deferred 1, deferred 0
}