So, im trying to classify objects of food category or tech category, as an object by categories as a final result. I have this input for the arguments in my function and then my end result should return me an object with both

{
 tech:  [ { tech product }, { tech product } ],
 food:  [ { food product }, { food product } ],
}

So what i have is a function where i try to construct an array with objects classifying the products. So far this is what i have been able to develop is this code, but for some reason I only get it to return me an empty object, not an object with both categories as I'm trying to.

function sortProducts (matrix) {
  const matrixResult = {};
  for (i = 0; i < matrix.length; i  ){
    let techProd = matrix[i];
    let techCategory = matrix[i].category;
    let techCategFilter = techCategory === ‘tech’;
    if (techCategFilter){
      let arrTech = []
      arrTech.push (techProd[i]);
      matrixResult.tech = arrTech;
    }
  }
   for (i = 0; i < matrix.length; i  ){
    let foodProd = matrix[i];
    let foodCategory = matrix[i].category;
    let foodCategFilter = foodCategory === ‘food’;
    if (foodCategFilter){
      let arrFood = []
      arrFood.push (foodProd[i]);
      matrixResult.food = arrFood;
    }
  }
  return matrixResult;
}

What am i missing or where am i messing up?

CodePudding user response：

Use reduce or filter, depending on how big your array is. I decided on forEach, since it is easier to read.

const result = {};

products.forEach(product => {
  const category = product.category;
  if (result[category]) {
    result[category].push(product);
  } else {
    result[category] = [product];
  }
})

CodePudding user response：

I see multiple issues with this code.

1. arrFood and arrTech arrays are initialized every time in loop so older objects pushed are getting overwritten every time in the if block and you will have only 1 object max always.
2. foodProd = matrix[i] will give you the food product object but then you push foodProd[i] to array which i guess will be undefined.

Try this (fixed the above issues and also shorten little bit):

function sortProducts (matrix) {
  const matrixResult = { tech: [], food: []};

  for (i = 0; i < matrix.length; i  ){
    let techProd = matrix[i];
    if (techProd.category === 'tech'){
      matrixResult.tech.push (techProd);
    }
  }
   for (i = 0; i < matrix.length; i  ){
    let foodProd = matrix[i];
    if (foodProd.category === 'food'){
      matrixResult.food.push (foodProd);
    }
  }
  return matrixResult;
}

you can as well use forEach instead of looping or reducer as suggested by @HPSingh.

forEach example:

var matrixResult = { tech: [], food: []};
matrix.forEach( obj => {
  if(obj.category === 'food') matrixResult.food.push(obj);
  else if(obj.category === 'tech') matrixResult.tech.push(obj);
});