I am fairly new to JS, I am struggling with a problem where there is an array of objects and i want to return true if any key value pair in the object is duplicate

```
var lookupValues = [{"key":"xiomi","value":"phone","id":1},{"key":"samsung","value":"tab",id:2},{"key":"blackberry","value":"phone","id":3},{"key":"xiomi","value":"tab","id":4},{"key":"asus","value":"phone",id:5}]}

```

Since key: "Xiomi" came twice so function should return true

i tried using lodash functions

```
var uniqueLookup =_uniqBy(lookupValues,'key')
if(_.isEqual(uniqueLookup, lookup)) return true

```

works but i guess i am missing something