defer+recover mechanism for error handling#
In Go, we pursue elegant code and introduce the mechanism: defer+recover mechanism to capture and handle errors
package main
import "fmt"
func main() {
test()
fmt.Println("Division operation above executed successfully")
fmt.Println("Executing the following logic normally")
}
func test() {
defer func() {
// Call the built-in recover function to capture errors:
err := recover()
// If no error is captured, the return value is the zero value: nil
if err != nil {
fmt.Println("Error has been captured")
fmt.Println("The error is:", err)
}
}()
num1 := 10
num2 := 0
result := num1 / num2
fmt.Println(result)
}
Result of execution:
Error has been captured
The error is: runtime error: integer divide by zero
Division operation above executed successfully
Executing the following logic normally
Custom error handling#
To create custom errors, you need to call the New function in the errors package: returns an error type
If the program encounters an error and wants to interrupt and exit the program: use the panic function in the builtin package
package main
import (
"errors"
"fmt"
)
func main() {
e := test2()
panic(e) // If an error occurs, it will interrupt and exit the program
fmt.Println("Division operation above finished executing")
fmt.Println("Executing the following logic normally")
}
func test2() (err error) {
num1 := 10
num2 := 0
if num2 == 0 { // If num2 is 0, return an error
return errors.New("Program encountered an error, divisor cannot be 0") // The New function here returns an error type
} else { // If num2 is not 0, execute normally
result := num1 / num2
fmt.Println(result)
return nil
}
}
Result of execution:
panic: Program encountered an error, divisor cannot be 0
goroutine 1 [running]:
main.main()
E:/Golang/demo/Error Handling/test2.go:10 +0x27