Go Tutorial · Control Flow · Lesson 10 of 30

Go If Else

Conditions, if with a short statement, and error checks.

if, else if, else

No parentheses around the condition; braces are required:

Example 1

package main

import "fmt"

func main() {
	temp := 31
	if temp > 30 {
		fmt.Println("Hot")
	} else if temp > 20 {
		fmt.Println("Warm")
	} else {
		fmt.Println("Cold")
	}
}

Output

Hot

Run this on your computer — see “Get Started” for setup.

if with a short statement

if can start with a statement whose variables are scoped to the if/else blocks. You'll see this everywhere for error handling:

Example 2

package main

import (
	"fmt"
	"strconv"
)

func main() {
	if n, err := strconv.Atoi("42"); err == nil {
		fmt.Println("parsed", n)
	}
	if _, err := strconv.Atoi("forty-two"); err != nil {
		fmt.Println("error:", err)
	}
}

Output

parsed 42
error: strconv.Atoi: parsing "forty-two": invalid syntax

Run this on your computer — see “Get Started” for setup.

Test yourself

Are parentheses required around an if condition in Go?

Yes
No

Show answer

Answer: No