JavaScript merging objects by id

Question

What\'s the correct way to merge two arrays in Javascript?

I\'ve got two arrays (for example):

var a1 = [{ id : 1, name : \"test\"}, { id : 2, name :         


        

Answer 1

reduce version.

var a3 = a1.concat(a2).reduce((acc, x) => {
    acc[x.id] = Object.assign(acc[x.id] || {}, x);
    return acc;
}, {});
_.values(a3);

I think it's common practice in functional language.