{viewContas && viewContas.map(vc => {
                        if(auth === vc.authorId)
                            return (
                                <tr key={vc.id}>
                                    <td>{vc.data}</td>
                                    <td>{vc.desc}</td>
                                    <td>R${vc.price}</td>
                                    <td>

let data = [
    {data: 1/1, desc: 'conta de gás', price: 138},
    {data: 1/1, desc: 'conta de gás', price: 139},
    {data: 1/1, desc: 'conta de gás', price: 140},
 ]

let prices = data.map( (v,i) => {
    return v.price;
})

console.log( prices.reduce( (a,b) => {
    return a+b;
}) );