Conditionals

Conditionals let your program choose what to do based on a boolean expression. Go uses if and else.

Basic if

No parentheses around the condition, but braces are required.

age := 20
if age >= 18 {
    fmt.Println("Adult")
}

if / else

score := 70
if score >= 60 {
    fmt.Println("Pass")
} else {
    fmt.Println("Fail")
}

else if

grade := 85
if grade >= 90 {
    fmt.Println("A")
} else if grade >= 80 {
    fmt.Println("B")
} else {
    fmt.Println("C or lower")
}

if with a short statement

You can run a statement before the condition. Variables declared there are only visible inside the if/else.

if n := 10; n%2 == 0 {
    fmt.Println(n, "is even")
} else {
    fmt.Println(n, "is odd")
}

This pattern keeps temporary variables scoped tightly to where they are used.