LWC: Why is string.split not working?

Question

Why is string.split() not working. I am getting an error message that it can't read undefined .split method. The code is

temp;
        @wire(fetchUsers)
            WiredType({ error, data }){
                for (var key in data) {
                
    //data has 1 element only.
                    this.temp = JSON.stringify(data[key].Users__c);
                }
                console.log(this.temp.split('a'));
               
            }

Answer 1

string.split is not working because it's not a string that you are trying to split - it's either undefined or null

If your users result is an array of objects, then it might be better to use a non keyed iterator. ie:

data.forEach( datum => {
  this.temp = datum.Users__c;
});

Not having the data structure it's hard to get any more precise than this.