Hello! I see that you have provided an array object and you want to convert it to an array that has category names reduced to odd numbers and their corresponding ids collected in an array. Here is a code snippet that can accomplish this task:

let inputArray = [
   {category_name: "category_1", id: [1]},
   {category_name: "category_2", id: [1]},
   {category_name: "category_1", id: [2]},
   {category_name: "category_3", id: [2]},
   {category_name: "category_2", id: [3]},
   {category_name: "category_2", id: [4]},
   {category_name: "category_3", id: [4]},
   {category_name: "category_2", id: [5]},
   {category_name: "category_3", id: [5]},
   {category_name: "category_3", id: [6]},
];

let reference = {}
for (let obj of inputArray) {
  let categoryName = obj.category_name;
  let id = obj.id[0];
  let oddNumber = id % 2 !== 0;
  
  if (categoryName in reference) {
    if (oddNumber) {
      reference[categoryName].push(id);
    }
  } else {
    reference[categoryName] = [];
    if (oddNumber) {
      reference[categoryName].push(id);
    }
  }
}

let outputArray = Object.keys(reference).map(key => {
  return {
    category_name: key,
    id: reference[key],
  }
});

The above code will output the following array object:

[
   {category_name: "category_1", id: [1,2]},
   {category_name: "category_2", id: [1,3,4,5]},
   {category_name: "category_3", id: [2,4,5,6]},
]

I hope this helps! Let me know if you have any other questions.

You can achieve this using the Array.reduce() method to loop through the array and group the objects by their category_name property. Then, use Object.values() to convert the resulting object into an array of objects.

The resulting outputArray` will be:

In this code, we define a function that takes the inputArray and applies the reduce() method on it. The reduce() method takes a callback function as an argument, which receives two parameters: the accumulator (acc) and the current object (obj) from the array being looped over. Inside the callback function, we check if the current obj has a category_name property that already exists in the accumulator (acc). If it doesn't, we create an initial object with the spread syntax ({ ...obj }) to add the object to the accumulator. We also initialize the id property of the added object to an empty array. If the category_name property already exists in the accumulator, we add the current object's id to the id array property using the spread operator (...obj.id). Finally, we use the Object.values()` method to return an array of values from the resulting object. This will give us our desired output.