# Go Error Handling Basics
###### tags: `golang`
[TOC]

# Nil Value
Means a value has not been initialized.

**Other Languages:**
>Javascript > null
>Java > null
>Swift > nil
>Python > None
>Ruby > nil[color=orange]

# Error Value
Go does not have **try catch statements or exceptions** like other languages.

***Let's take these functions as example:***
* func Itoa(i int) string -> never has errors b/c any int can converted into string
* func Atoi(s string) (int, error) -> this one returns an error type, if string cannot be converted into int.

**Note:**
In **Atoi function** error will be nil if it success, otherwise it would be a non-nil one. This method will fail if input a wording or even a float number.

**Success Example:**

i, err := strconv.Atoi("8")
fmt.Println("Converted N: ", i)
fmt.Println("Returned Err: ", err)

//Printed Answer
// Converted N:  8
// Returned Err:  <nil>

**Fail Example:**

i, err := strconv.Atoi("hello")
fmt.Println("Converted N: ", i)
fmt.Println("Returned Err: ", err)
    
//Printed Answer
// Converted N:  0
// Returned Err:  strconv.Atoi: parsing "hello": invalid syntax

As we can see, if there is an error, the int will just automatically become 0 and error will not be nil.

# How to handle Errors in GO?
In Golang we would just check whether the error is nil or not, to see whether there is any error.

**Note:** Atoi converts **String Value to Int value**.

if len(os.Args) > 1 {
    printValue()
} else {
    fmt.Println("No value given!")
}

// =========

func printValue() {
    input := os.Args[1]

    i, err := strconv.Atoi(input)
    if err != nil {
        fmt.Println("It Failed!")
        fmt.Println("Returned Err: ", err)
        return
    }

    fmt.Println("Converted N: ", i)
}