Question 232868 in Javascript Question posted in
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Count occurence of a list in different arrays (javascript)

I have a list like this :

var list = [apple, watermelon, pineapple]

And an array like this :

var array = { 
fruit : [ [apple], [apple, watermelon], [pineapple, watermelon], [watermelon], [pineapple], [apple, pineapple] ]

count : [4, 7, 5, 3, 3, 2]
}

I want to create a new array with the occurence of each fruits and to obtain this :

result = 
{
fruits : [apple, watermelon, pineapple]
count : [13, 15, 10]

I tried this :

var result = {
    trigger : [apple, watermelon, pineapple],
    count : []
}
for (i=0; i < array.fruits.length; i++){
    var k = 0
    for (j in result.trigger){
        if (array.fruits[i].includes(j)) {
            k += array.count[i]
        }
        result.count.push(k)
    }
}

But I get 0 for all counts

Thanks in advance for helping

Tags:

2

Answers


  1. 0 
    var list = ['apple', 'watermelon', 'pineapple']

var array = {
  fruit: [
    ['apple'],
    ['apple', 'watermelon'],
    ['pineapple', 'watermelon'],
    ['watermelon'],
    ['pineapple'],
    ['apple', 'pineapple']
  ],

  count: [4, 7, 5, 3, 3, 2]
}

const values = Array(list.length).fill(0)

// for each item of array.fruit
for (let i = 0; i < array.fruit.length; i += 1) {
  // for each fruit in subarray
  for (const fr of array.fruit[i]) {
    // find index in list
    const index = list.indexOf(fr)
    // add count of fruits
    values[index] += array.count[i]
  }
}

 

console.log(values)
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  2. 0

    You can use Array#reduce and check in each iteration whether a fruit in array.fuits[i] is in your list. If that is the case increase the according counter in your reducer accumulator.

    const list = ["apple", "watermelon", "pineapple"];
const array = {
  fruit: [
    ["apple"],
    ["apple", "watermelon"],
    ["pineapple", "watermelon"],
    ["watermelon"],
    ["pineapple"],
    ["apple", "pineapple"]
  ],
  count: [4, 7, 5, 3, 3, 2]
};

const result = array.fruit.reduce((acc, curr, i) => {
  curr.forEach(fruit => (acc[list.indexOf(fruit)] += array.count[i]));
  return acc;
}, Array(list.length).fill(0));

console.log(result);
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