I'm trying to pass a list of string from Apex controller to Javascript but it does not seem to work

Code I tried:

Apex class

 public static List<String> getGroups(){
     string names;
     List<String> Groupnames = new List<String>();
     Http http = new Http();
     HttpRequest request = new HttpRequest();
     HttpResponse res = http.send(request);
     LIST<Object> arr = (LIST<Object>) JSON.deserializeUntyped(res.getBody());
     for(integer i = 0; i < arr.size(); i++){
         Map<String, Object> firstMap = (Map<String, Object>)arr[i];
         names = (String)firstMap.get('name');
     return Groupnames;


listofgroup:function(component, event, helper){
    var action = component.get("c.getGroups");
    action.setCallback(this, function(response){
        //var state = response.getState();
        // if(state === 'SUCCESS'){
            var res = response.getReturnValue();
            for(var i = 0; i < res.length; i++){
                //set the values here
    // }

dont know where I'm going wrong

1 Answer 1


Looks like you have forgotten to actually call (enqueue) the action.

Like this:

action.setCallback(this, function(response){
  //your other stuff
//add here:

In your callback, to use as a select list, process something like this:

let groupValues = [];
let res = response.getReturnValue();
res.forEach( (value)=>{
  • i completely missed that.. how can i check what is inside v.lstGroup
    – Tejas
    Commented Apr 6, 2021 at 4:50
  • might be easiest to console.log it... console.log(JSON.stringify(component.get("v.lstGroup"))). Because it's a list of strings, you can also iterate it easily. Are you using it as a source for a picklist? Glad to help!! Commented Apr 6, 2021 at 4:53
  • Thank you @Casper Harmer
    – Tejas
    Commented Apr 6, 2021 at 4:54
  • 1
    Added a wee bit extra to show how to add the combobox items Commented Apr 6, 2021 at 7:05
  • 1
    Thankyou @Caspar Harmer you made my day..
    – Tejas
    Commented Apr 6, 2021 at 7:29

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