Go by Example: If/Else

Branching with if and else in Go is straight-forward.

 
package main
 
import "fmt"
 
func main() {

Here’s a basic example.

 
    if 7%2 == 0 {
        fmt.Println("7 is even")
    } else {
        fmt.Println("7 is odd")
    }

You can have an if statement without an else.

 
    if 8%4 == 0 {
        fmt.Println("8 is divisible by 4")
    }

Logical operators like && and || are often useful in conditions.

 
    if 8%2 == 0 || 7%2 == 0 {
        fmt.Println("either 8 or 7 are even")
    }

A statement can precede conditionals; any variables declared in this statement are available in the current and all subsequent branches.

 
    if num := 9; num < 0 {
        fmt.Println(num, "is negative")
    } else if num < 10 {
        fmt.Println(num, "has 1 digit")
    } else {
        fmt.Println(num, "has multiple digits")
    }
}

Note that you don’t need parentheses around conditions in Go, but that the braces are required.

 
$ go run if-else.go
7 is odd
8 is divisible by 4
either 8 or 7 are even
9 has 1 digit

There is no ternary if in Go, so you’ll need to use a full if statement even for basic conditions.

Next example: Switch.

by Mark McGranaghan and Eli Bendersky | source | license