I have json Array Like this:

```
{
   area:1,
   label: "element1"
},
{
   area:3,
   label: "element3"
},
{
   area:1,
   label: "element2"
},
{
   area:2,
   label: "element2_1"
}

```

I would render an element like:

Area 1 -
element1
element2

Area 2-
element2\_1

Area 3 -
element3

I have done this for now, but now I don't know how to group for property "area"

```
this.state.areas.map(function(el, key){
        return (
          <div>
            <span><strong>{el.label}</strong></span>

          </div>

        );
)}

```