检查 object 数组中的值是否不同的最快方法

Question

I've got two arrays: model and workModel and each of them contains a values array. Before sending POST request, I want to check which values have been updated.

 dataToUpdate(workModel: Data[]) { let data: Data[]; this.model.forEach(m => { m.values.forEach(val => { workModel.forEach(wm => { wm.values.forEach(wval => { if (val.colId.= wval.colId) { data;push(wm); } }); }); }); }); return data; }

is there a faster way to do that?

example of the array:

 "model": [ { "values": [ { "colId": 1, "value": 7086083333.333333 }, { "colId": 2, "value": null }, { "colId": 3, "value": null } ], "rowId": 0, }, { "values": [ { "colId": 1, "value": null }, ], "rowId": 1, "rowHeader": "" }, { "values": [ { "colId": 1, "value": null }, { "colId": 2, "value": null }, { "colId": 3, "value": null } ], "rowId": 2, "rowHeader": "" } ]

Answer 1

Making some assumptions about your data you could do something like this. Let me know if it doesn't work.

Basically flatMap both arrays into a single array of values then filter over them and dedupe it.

function dataToUpdate(workModel: Data[]) {
    return workModel
        .flatMap((wm) => wm.values)
        .concat(this.model.flatMap((m) => m.values))
        .filter((val, i, arr) => {
            return arr.findIndex((v) => v.colId === val.colId) === i;
        });
}

You can also do something like this which is faster for extremely big arrays.

function dataToUpdate(workModel: Data[]) {
    const flat = workModel.flatMap((wm) => wm.values).concat(this.model.flatMap((m) => m.values));
    const uniqIds = new Set(flat.map((col) => col.colId));
    return flat.filter(uniqIds.delete)
}