In addition to what others said (especially PeterSO and dskinner—in his comment to the Peter’s answer), note several important things: You can call a method like a simple function In Go, you can call any method function not as a method on a receiver but rather as a regular function—simply by qualifying its name with … Read more
In json package documentation : Pointer values encode as the value pointed to. A nil pointer encodes as the null JSON object. So you can store a pointer to a string which will be encoded as a string if not nil and will be encoded as “null” if nil type student struct { FirstName *string … Read more
goinstall is now history goinstall was replaced by go get. go get is used to manage external / 3rd party libraries (e.g. to download them, update them, install them etc). Type go help get to see command line help, or check out these pages: Command go About the go command (blog post) If you want … Read more
Interfaces are too big of a topic to give an all-depth answer here, but some things to make their use clear. Interfaces are a tool. Whether you use them or not is up to you, but they can make code clearer, shorter, more readable, and they can provide a nice API between packages, or clients … Read more
If you are using a Unix-based system (e.g. Linux or Mac OSX) you could try removing the debugging information included in the executable by building it with the -w flag: go build -ldflags “-w” prog.go The file sizes are reduced dramatically. For more details visit the GDB’s page: http://golang.org/doc/gdb
Before Golang 1.6, concurrent read is OK, concurrent write is not OK, but write and concurrent read is OK. Since Golang 1.6, map cannot be read when it’s being written. So After Golang 1.6, concurrent access map should be like: package main import ( “sync” “time” ) var m = map[string]int{“a”: 1} var lock = … Read more
One possible idea is to write separate constructor function //Something is the structure we work with type Something struct { Text string DefaultText string } // NewSomething create new instance of Something func NewSomething(text string) Something { something := Something{} something.Text = text something.DefaultText = “default text” return something }
In order to do that you need reflect. package main import ( “fmt” “reflect” ) func main() { // one way is to have a value of the type you want already a := 1 // reflect.New works kind of like the built-in function new // We’ll get a reflected pointer to a new int … Read more
Yes, this example is correct. It is important that the wg.Add() happens before the go statement to prevent race conditions. The following would also be correct: func main() { var wg sync.WaitGroup wg.Add(1) go dosomething(200, &wg) wg.Add(1) go dosomething(400, &wg) wg.Add(1) go dosomething(150, &wg) wg.Add(1) go dosomething(600, &wg) wg.Wait() fmt.Println(“Done”) } However, it is rather … Read more
The question is not quite explicit, it can be interpreted in 2 ways, to one of which the answer is no, not possible; and the other to which the answer is yes, it’s possible. At runtime If the type name is provided as a string value, then at runtime it’s not possible as types that … Read more