I am learning array filter,reduce and map methods. while doing some exercises I got struct. I have array of object like this

```
var p=[
  {
    "key": "a",
    "value": 4
  },
  {
    "key": "b",
    "value": 3
  },
  {
    "key": "c",
    "value": 3
  },
  {
    "key": "d",
    "value": 6
  },
  {
    "key": "e",
    "value": 1
  }
]

```

and this what I did

```
var column=p.reduce((accumulator, currentValue, currentIndex, array)=>{
var arr=[];
arr[currentValue.key]=currentValue.value;
console.log(accumulator)
return (accumulator.push(arr));
},[]) 
console.log(column)

```

and I am expecting array like this

```
[['a',4],['b',3],['c',3],['d',6],['e',1]]

```

after first iteration I got this error:

> 
> accumulator.push is not a function
> 
> 
> 

I don't know what I am doing wrong.