deQueue is looping infinitely on the fail case, which is blocking the CPU. Goroutines don’t yield while doing CPU work. GOMAXPROCS needs to be >= 2 to get CPU parallelism. just for kicks, here’s a threadsafe, nonblocking queue implementation using higher-order channels: https://gist.github.com/3668150 solved What’s wrong with my golang code? [duplicate]
Once you have your map constructed, you can access a value of the map by providing the key. The syntax is: value := myMap[myKey] The key’s type can be any type that can be evaluated by a comparison operator ( >=, ==, <=, etc…). For your example it looks like you are using strings for … Read more
who can help me? in php has bcadd function bcadd and its friends are arbitrary precision arithmetic functions (that’s why they operate on strings and not floats). A float has limited precision. In effect, bcmath offers infinitely more precision than a float. Use math/big. 0 solved How can I add two arbitrary large numbers in … Read more
Since you cannot describe your data in a struct then your options are to: Use a json.Decoder to convert the values to your desired types as they are parsed. Parse the document into a generic interface and post-process the value types. Option #1 is the most flexible and can likely be implemented to be more … Read more
Answering your question: Fortunately, Go prevents certain types of programmers errors. It just won’t let you compile the program if you forget one of the values that the function returns. It’s a good practice to return errors in Go, read Errors section of Effective Go Library routines must often return some sort of error indication … Read more
Thanks @Peter urlLogin := “http://kasant.gvc.oao.rzd:8888/kasant/login?” formData := url.Values{ “dor_user”: {“51”}, “login”: {“nvivc”}, “pass”: {“51256”}, } cookieJar, _ := cookiejar.New(nil) client := &http.Client{ Jar: cookieJar, } respp, _ := client.Post(urlLogin, “application/x-www-form-urlencoded”, bytes.NewBufferString(formData.Encode())) defer respp.Body.Close() solved I can not send a post request with Golang?
TL;DR Just use json.Unmarshal. You can wrap it lightly, using your transport, and call json.Unmarshal (or with a json.Decoder instance, use d.Decode) on your prebuilt JSON bytes and the v interface{} argument from your caller. Somewhat longer, with an example Consider how json.Unmarshal does its own magic. Its first argument is the JSON (data []byte), … Read more
form json pkg you can encoding and decoding JSON format package main import ( “encoding/json” “fmt” ) type Species struct { Human []Info `json:”human”` Animal []Info `json:”animal”` } type Info struct { Name string `json:”name”` Number string `json:”number”` } func main() { data := Species{ Human: []Info{ Info{Name: “dave”, Number: “00001”}, Info{Name: “jack”, Number: “00002”}, … Read more
int in func package main import “fmt” func zero(x int) int { x = 0 return x } func main() { x := 5 x = zero(x) fmt.Println(x) } solved What’s wrong with this simple script?
Here slice nums[:i] is created by slicing a bigger array nums. This leads to it having enough capacity to extend in place. So an operation like append(nums[:i], nums[i+1:]…) causes the elements in nums getting overridden by elements from nums[i+1:]. This mutates the original array and hence the behaviour. As suggested by @icza the concept has … Read more
There are two problems: #1 You need to have both files in the same directory with the same package name; namely, main. #2 You need to compile and execute all files in this directory which you can do either using: go run ./… to execute all files in this directory, or, go run app.go main.go … Read more
This occurs, as the error message says, when you try to dereference (use) nil. Without knowing which line the error was reported on, I would have to guess it’s here: cd, _ := r.Cookie(“hello”) if cd.Value == “username” { // <– This line // do … } Because you’re discarding the error from r.Cookie() instead … Read more
Try not to use reflect. But if you must use reflect: A reflect.Value value has a Type() function, which returns a reflect.Type value. If that type’s Kind() is reflect.Map, that reflect.Value is a value of type map[T1]T2 for some types T1 and T2, where T1 is the key type and T2 is the element type. … Read more
If you’re looking for something like person[property] like you do in Python or JavaScript, the answer is NO, Golang does not support dynamic field/method selection at runtime. But you can do it with reflect: import ( “fmt” “reflect” ) func main() { type person struct { name string age int } v := reflect.ValueOf(person{“Golang”, 10}) … Read more
The problem is with the pointer assignments as you build the slice you are trying to reference. The addresses keep changing. func main(){ var lump []int // A loop to build a slice of `int`’s from 0 size to 8 size // and print each index address for i:= 0; i < 8; i++{ lump … Read more