比较两个对象并在javascript中提取具有相同键的对象

Question

I have the following two objects

var productionTime= [
    {Rob3: 20},
    {Rob8: 100},
    {Rob4: 500},
    {Rob1: 100},
    {Rob5: 500}
];
var Busytime= [
    {Rob4: 10},
    {Rob3: 200},
    {Rob8: 100},
    {Rob5: 200},
    {Rob1: 100}
];

Now I want to divide each item in 'productionTime' by its respective 'BusyTime' which have the same key. For example productionTime.Rob3 should be divided by BusyTime.Rob3 and productionTime.Rob8 should be divided by BusyTime.Rob8 and so on.

How can I do this with array.find() or array.filter() in javascript/nodejs?

PS: I know i can do it by using two nested forEach loops but that is I guess very slow

Answer 1

You could use a hash table and a single loop for every array.

 var productionTime = [{ Rob3: 20 }, { Rob8: 100 }, { Rob4: 500 }, { Rob1: 100 }, { Rob5: 500 }]; busytime = [{ Rob4: 10 }, { Rob3: 200 }, { Rob8: 100 }, { Rob5: 200 }, { Rob1: 100 }], hash = Object.create(null); busytime.forEach(function (o) { var key = Object.keys(o)[0]; hash[key] = o[key]; }); productionTime.forEach(function (o) { var key = Object.keys(o)[0]; o[key] /= hash[key]; }); console.log(productionTime); 

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Answer 2

Convert both arrays to object using Object#assign and the spread syntax . Get the keys from one of them using Object#keys , and iterate the keys using Array#map . Create a new object for each key using shorthand property names :

 const productionTime = [{"Rob3":20},{"Rob8":100},{"Rob4":500},{"Rob1":100},{"Rob5":500}]; const Busytime= [{"Rob4":10},{"Rob3":200},{"Rob8":100},{"Rob5":200},{"Rob1":100}]; // create objects from both arrays const productionTimeObj = Object.assign({}, ...productionTime); const busytimeObj = Object.assign({}, ...Busytime); // get the keys from one of the objects, and iterate with map const result = Object.keys(productionTimeObj).map((key) => ({ // create a new object with the key, and the result of the division [key]: productionTimeObj[key] / busytimeObj[key] })); console.log(result);