How grouped sort array of objects based on object's value?

Question

I have array of objects like this:

var points = [{a: 4, b: 3, c:'parent'}, {a: 1, b:5, c:'child'}, {a: 5, b: 2, c:'child'}, {a: 1, b: 2, c:'parent'}, {a: 3, b: 1, c:'child'}];

I need to sort it on "a" object's value. But the problem is if it has the "c" object's value "parent" the "c" object's value "child" should be next object of that and shouldn't be sorted.

At last I expect to have this sorted points array:

var sortedPoints = [{a: 1, b: 2, c:'parent'}, {a: 3, b: 1, c:'child'} ,{a: 4, b: 3, c:'parent'}, {a: 1, b:5, c:'child'}, {a: 5, b: 2, c:'child'}];

Answer 1

You need to group parents and children, sort and get a flat array.

 var points = [{ a: 4, b: 3, c: 'parent' }, { a: 1, b: 5, c: 'child' }, { a: 5, b: 2, c: 'child' }, { a: 1, b: 2, c: 'parent' }, { a: 3, b: 1, c: 'child' }], sorted = points.reduce((r, o) => { if (o.c === 'parent') r.push([o]); else r[r.length - 1].push(o); return r; }, []).sort(([{ a }], [{ a: b }]) => a - b).flat(); console.log(sorted);

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