Count objects in array js node

I want to create a new variable that will count all the names and them as a assignments says but I am kind of stuck.

I have an array with names.

names = [Jan, Jan, Jana]

I would like to count these names, which is quite easy but what I am struggling with is putting them as the assignment says below.

const dtoOut = {
 chartData: {
    all: [
     {label: "Jan", value: 2},
     {label: "Jana", value: 1},

any help?

>Solution :

if your keys do not change this is one easy way

const result = {
 chartData: {
   all: names.reduce((acc, curr) => {
     const obj = acc.find(o => o.label === curr);
     if (obj) {
       obj.value += 1;
     } else {
       acc.push({label: curr, value: 1});
     }
     return acc;
   }, [])
 }
};