使用其他变量中的数据引用go中的变量？

I am relatively new to go/ coding.I want to be able to reference a variable by using a variable.

var a = make([]int,0)
var b = make([]int,0)
var c = make([]int,0)

I have some slices defined

set := input.Ask("Which set would you like to input to (a, b, c):")
for true {
  num := input.Ask("Number:")
  strings.toLower(set) = append(strings.toLower(set), num)
}

I want the "strings.tolower" part output a string, which it does, that will allow me to select one of the variables I have defined.

This sounds like the general description of a string-keyed map: you have three values, and you want to choose which one to use based on some string value.

maps := map[string][]int{}

set := input.Ask("Which set would you like to input to:")
set = strings.toLower(set)
for true {
    num := input.Ask("Number:")
    maps[set] = append(maps[set], num)
}

If it's important to you to only be able to use one of these three values, you can prepopulate the map

maps := map[string][]int{
    "a": nil,
    "b": nil,
    "c": nil,
}
set := input.Ask("Which set would you like to input to (a, b, or c):")
set = strings.toLower(set)
if _, ok := maps[set]; !ok {
    fmt.Println("I don't know about that set")
    return
}

There's more information on maps in the language spec.

You can do something like this:

var selected *[]int
switch strings.ToLower(set) {
  case "a": selected = &a
  ...
}
*selected = append(*selected, num)