slice

问题 I have a struct and the instance of that struct: type Obj struct { ssid string code string mit string // and other props (23) } var ValidObject = Obj { ssid: "AK93-KADJ9-92J76", code: "SKO-120O" mit: "MSLA-923-OKSW" } I want to create a slice of structs ( Obj ) which will contain ValidObject with only some fields changed. I think the best way to explain that would be using pseudo code, so here it is (using spread operator from JS :) ): var slc = []Obj{ { ...ValidObject, code: "Other value", }

问题 This question already has answers here : casting a cgo array into a slice (1 answer) Access C array of type const char * from Go (1 answer) Go slice backed by a C array [duplicate] (1 answer) What is the best (safest + most performant) way of getting a specific slice of bytes from an unsafe.Pointer (1 answer) What does (*[1 << 30]C.YourType) do exactly in CGo? (1 answer) Closed 8 months ago . I have a use-case where C code will call Go function (exported by building Go as shared library). All

问题 Code below will raise a runtime error when append reflect.Value of nil : package main import ( "fmt" "reflect" ) func main() { var list []interface{} v := reflect.ValueOf(list) v = reflect.Append(v, reflect.ValueOf(1)) // [1] v = reflect.Append(v, reflect.ValueOf("1")) // [1, 1] v = reflect.Append(v, reflect.ValueOf(nil)) // runtime error fmt.Println(v) } So why there is a runtime error? how can I use reflect.Append to add a nil to interface{} slice? 回答1: interface{} is an interface type, and

问题 Code below will raise a runtime error when append reflect.Value of nil : package main import ( "fmt" "reflect" ) func main() { var list []interface{} v := reflect.ValueOf(list) v = reflect.Append(v, reflect.ValueOf(1)) // [1] v = reflect.Append(v, reflect.ValueOf("1")) // [1, 1] v = reflect.Append(v, reflect.ValueOf(nil)) // runtime error fmt.Println(v) } So why there is a runtime error? how can I use reflect.Append to add a nil to interface{} slice? 回答1: interface{} is an interface type, and

问题 I want to search a list for the occurence of a value (x) and return that value and a number, say 2, of the values above and below x in the index. Value x might appear in the list multiple time. Input in = ['a','b','c','d','x','e','f','g','h','i','x','j','k','l'] Output out = ['c','d','x','e','f','h','i','x','j','k'] Thanks for any help or suggestions 回答1: In [8]: lis = ['a','b','c','d','x','e','f','g','h','i','x','j','k','l'] #create a new list containing all the index positions of 'x' In [9]

问题 I have a variable length multi-dimensional like the following: listD = [[[[53, 54], [129, 130]]], [[[51, 51], [132, 132]]], [[[39, 39], [144, 144]], [[53, 54], [129, 130]]], [[[39, 39], [146, 146]], [[54, 54], [130, 130]]], [[[54, 53], [130, 129]]], [[[52, 52], [132, 132]]] ] I need to pick out the first element in each of the innermost of the lists. The output should look like this: outlist=[[[[53, 54]]], [[[51, 51]]], [[[39, 39]], [[53, 54]]], [[[39, 39]], [[54, 54]]], [[[54, 53]]], [[[52,

问题 I have a variable length multi-dimensional like the following: listD = [[[[53, 54], [129, 130]]], [[[51, 51], [132, 132]]], [[[39, 39], [144, 144]], [[53, 54], [129, 130]]], [[[39, 39], [146, 146]], [[54, 54], [130, 130]]], [[[54, 53], [130, 129]]], [[[52, 52], [132, 132]]] ] I need to pick out the first element in each of the innermost of the lists. The output should look like this: outlist=[[[[53, 54]]], [[[51, 51]]], [[[39, 39]], [[53, 54]]], [[[39, 39]], [[54, 54]]], [[[54, 53]]], [[[52,

问题 I have a variable length multi-dimensional like the following: listD = [[[[53, 54], [129, 130]]], [[[51, 51], [132, 132]]], [[[39, 39], [144, 144]], [[53, 54], [129, 130]]], [[[39, 39], [146, 146]], [[54, 54], [130, 130]]], [[[54, 53], [130, 129]]], [[[52, 52], [132, 132]]] ] I need to pick out the first element in each of the innermost of the lists. The output should look like this: outlist=[[[[53, 54]]], [[[51, 51]]], [[[39, 39]], [[53, 54]]], [[[39, 39]], [[54, 54]]], [[[54, 53]]], [[[52,

问题 I have a slice: Keys []* datastore.Key How could I index one of them in the template file? I guessed {{.Keys[3] }} , but that doesn't work and I searched a lot but with no clue. Any suggestions would be welcome, thanks. 回答1: Use the index command like so: {{index .Keys 3}} 回答2: As stated in the html/template package, the majority of examples are actually located in the text/template pkg docs. See http://golang.org/pkg/text/template/ From the docs index Returns the result of indexing its first

问题 I have a slice: Keys []* datastore.Key How could I index one of them in the template file? I guessed {{.Keys[3] }} , but that doesn't work and I searched a lot but with no clue. Any suggestions would be welcome, thanks. 回答1: Use the index command like so: {{index .Keys 3}} 回答2: As stated in the html/template package, the majority of examples are actually located in the text/template pkg docs. See http://golang.org/pkg/text/template/ From the docs index Returns the result of indexing its first