JavaScript - Count the Objects in Array and Remove Duplicate Object-CodePudding

I have an array like this:

var objects = [{
    name: "brilliance_denali_(best)"
    shadowColor: "warmWhite"
    wattage: {upPrice: 10, value: '10W'}
},
{
    name: "brilliance_denali_(best)"
    shadowColor: "warmWhite"
    wattage: {upPrice: 10, value: '10W'}
},
{
    name: "brilliance_denali_(best)"
    shadowColor: "red"
    wattage: {upPrice: 12, value: '12W'}
},
{
    name: "bullet_lights"
    shadowColor: "blue"
    wattage: {upPrice: 28, value: '10W'}
}]

And I want to calculate the count based on name && shadowColor && wattage.value. Get the count and remove the duplicates with result array like:

var result = [{
    name: "brilliance_denali_(best)"
    shadowColor: "warmWhite"
    wattage: {upPrice: 10, value: '10W'},
    count: 2
},
{
    name: "brilliance_denali_(best)"
    shadowColor: "red"
    wattage: {upPrice: 12, value: '12W'},
    count: 1
},
{
    name: "bullet_lights"
    shadowColor: "blue"
    wattage: {upPrice: 28, value: '10W'},
    count: 1
}]

How can I achieve this result using array.reduce ?

CodePudding user response：

You use the classic indexOf trick.

const cleaned = yourlist.filter((entry, position) => {
  yourlist.findIndex(e => e.name === entry.name && ...) === position;
});

That is: remove any element that exists in the array, based on the findIndex function (which lets your find things based on a match function), but does NOT have the index of the element you're looking at right now.

CodePudding user response：

You can first do object count in array and then add that count to initial objects

var objects = [{
    name: "brilliance_denali_(best)",
    shadowColor: "warmWhite",
    wattage: {upPrice: 10, value: '10W'}
},
{
    name: "brilliance_denali_(best)",
    shadowColor: "warmWhite",
    wattage: {upPrice: 10, value: '10W'}
},
{
    name: "brilliance_denali_(best)",
    shadowColor: "red",
    wattage: {upPrice: 12, value: '12W'}
},
{
    name: "bullet_lights",
    shadowColor: "blue",
    wattage: {upPrice: 28, value: '10W'}
}]


const counter = objects.reduce((acc,curr)=>{
   const key = JSON.stringify(curr);
   acc[key] = (acc[key] || 0)   1;
   return acc;
}, {});

const result = [];

for (const key in counter){
  const finalObj = JSON.parse(key);
  finalObj.count = counter[key];
  result.push(finalObj);
}

console.log(result)