reflect.Select() Function in Golang with Examples Last Updated : 03 May, 2020 Comments Improve Suggest changes Like Article Like Report Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.Select() Function in Golang is used to executes a select operation described by the list of cases. To access this function, one needs to imports the reflect package in the program. Syntax: func Select(cases []SelectCase) (chosen int, recv Value, recvOK bool) Parameters: This function takes the following parameters: cases : This parameter is the list of cases. Return Value: This function returns the index of the chosen case. Below examples illustrate the use of the above method in Golang: Example 1: C // Golang program to illustrate // reflect.Select() Function package main import ( "fmt" "reflect" ) func main() { c := make(chan int, 1) vc := reflect.ValueOf(c) succeeded := vc.TrySend(reflect.ValueOf(123)) fmt.Println(succeeded, vc.Len(), vc.Cap()) vSend, vZero := reflect.ValueOf(789), reflect.Value{} branches := []reflect.SelectCase{ {Dir: reflect.SelectDefault, Chan: vZero, Send: vZero}, {Dir: reflect.SelectRecv, Chan: vc, Send: vZero}, {Dir: reflect.SelectSend, Chan: vc, Send: vSend}, } // use of Select() method selIndex, vRecv, sentBeforeClosed := reflect.Select(branches) fmt.Println(selIndex) fmt.Println(sentBeforeClosed) fmt.Println(vRecv.Int()) vc.Close() // Remove the send case branch this time, // for it may cause panic. selIndex, _, sentBeforeClosed = reflect.Select(branches[:2]) fmt.Println(selIndex, sentBeforeClosed) } Output: true 1 1 1 true 123 1 false Example 2: C // Golang program to illustrate // reflect.Select() Function package main import ( "fmt" "reflect" ) func main() { var sendCh = make(chan int) var increaseInt = func(c chan int) { for i := 0; i < 8; i++ { c <- i } close(c) } go increaseInt(sendCh) var selectCase = make([]reflect.SelectCase, 1) selectCase[0].Dir = reflect.SelectRecv selectCase[0].Chan = reflect.ValueOf(sendCh) counter := 0 for counter < 1 { // use of Select() method chosen, recv, recvOk := reflect.Select(selectCase) if recvOk { fmt.Println(chosen, recv.Int(), recvOk) } else { counter++ } } } Output: 0 0 true 0 1 true 0 2 true 0 3 true 0 4 true 0 5 true 0 6 true 0 7 true Comment More infoAdvertise with us Next Article reflect.Select() Function in Golang with Examples S SHUBHAMSINGH10 Follow Improve Article Tags : Go Language Golang-reflect Similar Reads reflect.Set() Function in Golang with Examples Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.Set() Function in Golang is used to assigns x to the value v. To access this function, one needs to imports the r 2 min read reflect.SliceOf() Function in Golang with Examples Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.SliceOf() Function in Golang is used to get the slice type with element type t, i.e., if t represents int, SliceO 1 min read reflect.SetBool() Function in Golang with Examples Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.SetBool() Function in Golang is used to sets v's underlying value. To access this function, one needs to imports 2 min read reflect.StructOf() Function in Golang with Examples Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.StructOf() Function in Golang is used to get the struct type containing fields. To access this function, one need 2 min read reflect.TrySend() Function in Golang with Examples Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.TrySend() Function in Golang attempts to send x on the channel v but will not block. To access this function, one 2 min read Like