如何把数组内相同的值，组成新的数组

僵了大半天

//原始数组
let arr = [
{ name: 'book', number: 10 },
{ name: 'paper', number: 10 },
{ name: 'ruber', number: 10 },
{ name: 'book', number: 20 },
{ name: 'paper', number: 40 },
{ name: 'ruber', number: 50 },
{ name: 'book', number: 70 },
{ name: 'paper', number: 80 },
{ name: 'ruber', number: 90 },
];
//目标转换成这样
let newArr = [
{ name: 'book', value: [10, 20, 70] },
{ name: 'ruber', value: [10, 40, 80] },
{ name: 'paper', value: [10, 50, 90] },
];

回答

function group(arr) {
    return Object.values(arr.reduce((result, item) => {
        const { name, number } = item;
        const { values = [] } = result[name] || {};
        values.push(number);
        result[name] = { name, values };
        return result;
    }, {}));
}

// TEST
group(arr);