For this exercise, my solution isn’t able to pass the FCC test. I manually checked it against the tests and the correct values do return… not sure where I’m going wrong, much appreciated for some help thanks!

here’s my solution:

```
let sym = (...args)=>{
return(
args.reduce((prev, curr)=>{
let prevSet = new Set(prev)
let currSet = new Set(curr)
let combArr=[...prevSet, ...currSet]
let setObj = {}
for(let i=0;i<combArr.length;i++){
if(setObj[combArr[i]]>=1){
setObj[combArr[i]]++
} else {
setObj[combArr[i]]=1
}
}
let x = []
for (let key in setObj){
if(setObj[key]==1){
x.push(key)
}
}
return x
}))
}
```