折叠算法

let newArr = [
{
name: 1,
type: 21
},
{
name: 11,
type: 2
},
{
name: 1,
type: 2
},
{
name: 1,
type: 2
},
{
name: 1,
type: 21
},
{
name: 11,
type: 2
},
{
name: 13,
type: 2
}
];
var result = {};
console.log(“start”, new Date().getTime());
newArr.forEach(
i => {
var k = i.name + “-” + i.type;
if (!(k in result)) {
result[k] = i;
i.count = 0;
} else {
console.log(“k”, k);
}
result[k].count++;
},
() => {
console.log(“end”, new Date().getTime());
}
);
console.log(“result”, result);
let dataArr = Object.values(result);
console.log(“dataArr”, dataArr);