if/else

Branching with if-else is similar to that of other languages. The expression does not need to be surrouned by parentheses ( ) but the braces { } are required.

i := 123;
if i > 100 {
    i = 100;
}
fmt.println(i);

An if statement can have a initial statement to execute before the condition. This is usually an assignment of a variable declaration; variables declared by the statement are only in the scope of the if statement.

if x := 12; x > 10 {
    fmt.println(x);
}

Variables declared by the if initial statement are also available inside any of the else blocks.

if x := -2; x < 0 {
    fmt.println("Negative x,", -x);
} else {
    fmt.println("Positive x,", x);
}

if-else statements can be chained together.

if x := 12; x == 0 {
    fmt.println("Zero");
} else if x < 10 {
    fmt.println("Single digits");
} else if x < 20 {
    fmt.println("Less than 20");
} else if x < 100 {
    fmt.println("Less than 100");
} else {
    fmt.println("Numbers go that high?");
}