// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // This file contains examples to embed in the Go 1 release notes document. package main import "log" func main() { stringAppend() mapDelete() mapIteration() multipleAssignment() structEquality() } func mapDelete() { m := map[string]int{"7": 7, "23": 23} k := "7" delete(m, k) if m["7"] != 0 || m["23"] != 23 { log.Fatal("mapDelete:", m) } } func stringAppend() { greeting := []byte{} greeting = append(greeting, []byte("hello ")...) greeting = append(greeting, "world"...) if string(greeting) != "hello world" { log.Fatal("stringAppend: ", string(greeting)) } } func mapIteration() { m := map[string]int{"Sunday": 0, "Monday": 1} for name, value := range m { // This loop should not assume Sunday will be visited first. f(name, value) } } func assert(t bool) { if !t { log.Panic("assertion fail") } } func multipleAssignment() { sa := []int{1, 2, 3} i := 0 i, sa[i] = 1, 2 // sets i = 1, sa[0] = 2 sb := []int{1, 2, 3} j := 0 sb[j], j = 2, 1 // sets sb[0] = 2, j = 1 sc := []int{1, 2, 3} sc[0], sc[0] = 1, 2 // sets sc[0] = 1, then sc[0] = 2 (so sc[0] = 2 at end) assert(i == 1 && sa[0] == 2) assert(j == 1 && sb[0] == 2) assert(sc[0] == 2) } func structEquality() { // Feature not net in repo. // type Day struct { // long string // short string // } // Christmas := Day{"Christmas", "XMas"} // Thanksgiving := Day{"Thanksgiving", "Turkey"} // holiday := map[Day]bool { // Christmas: true, // Thanksgiving: true, // } // fmt.Printf("Christmas is a holiday: %t\n", holiday[Christmas]) } func f(string, int) { } func initializationFunction(c chan int) { c <- 1 } var PackageGlobal int func init() { c := make(chan int) go initializationFunction(c) PackageGlobal = <-c }