How to store array values in an environment variable in Postman - arrays

Question

I am using a postman to automate apis.
Now I am using following request , lets say :-
{
"customerId": "{{currentClientId}}"
}
Where clientid is a dynamic variable whose value is substituted dynamically as 1 , 2, 3,4 so on..
I call this request multiple times using setNextRequest call in this eg lets say 10.This is being done using a counter variable. I am initialising the counter in my previous request to 0 and using for loop with value as counter as 10 calling the request 10 times.There is no response in body just successful http code 204.
I want to store all these clientids coming in request into an environment Client array variable so I wrote a following pre-request script:-
counter = pm.environment.get("counter");
ClientArray = pm.environment.get("ClientArray");
ClientArray.push(pm.environment.get("currentClientId"));
pm.environment.set("ClientArray",ClientArray);
In Test Script, wrote following code :-
counter = pm.environment.get("counter");
if(counter<=10) {
console.log("hi");
postman.setNextRequest("Request");
counter++;
pm.environment.set("counter",counter);
console.log("Counter",counter);
}
The above scipts is throwing
TypeError | ClientArray.push is not a function.
Could someone please advice how to achieve this.

Answer 1

When you retrieve a value from an environment variable like you're doing:
ClientArray = pm.environment.get("ClientArray");
You're not getting an array, you're getting a string which is why you're getting that error. You need to treat the variable like a string, append the currentClientId much like you do for the counter. Something like:
var currentClientIds = pm.environment.get("ClientArray");
currentClientIds = currentClientIds + "," + currentClientId
When you're done appending i.e. out of your loop simply take the string and convert it to an array:
var currentClientIds = pm.environment.get("ClientArray");
var idsArr = curentClientIds.split(',');