Go Control Flow

Go Control Flow

Resource Routing

• references/SWITCH-PATTERNS.md - Read when using switch statements, type switches, fallthrough, or labeled breaks.
• references/BLANK-IDENTIFIER.md - Read when using _, blank imports, unused compile-time assertions, or intentional discards.

---

If with Initialization

if and switch accept an optional initialization statement. Use it to scope variables to the conditional block:

if err := file.Chmod(0664); err != nil {
    log.Print(err)
    return err
}

If you need the variable beyond a few lines after the if, declare it separately and use a standard if instead:

x, err := f()
if err != nil {
    return err
}
// lots of code that uses x

Indent Error Flow (Guard Clauses)

When an if body ends with break, continue, goto, or return, omit the unnecessary else. Keep the success path unindented:

f, err := os.Open(name)
if err != nil {
    return err
}
d, err := f.Stat()
if err != nil {
    f.Close()
    return err
}
codeUsing(f, d)

Never bury normal flow inside an else when the if already returns.

---

Redeclaration and Reassignment