I am trying to sort some numbers, and I want to count the number of times that an array has a certain number.
My question is more about the structure of an the array than the counting the number part. I would like to build an array that looks like this below.
let numbers = [1,2,3,4,4,4,5,5,6];
How could I make the data structure below?
numbers[3].count // this will be equal to 3 after I loop through;
How do I make each part of the array have an object parameter?
Do I just loop through like so?
for (let i = 0; i < numbers.length; i++){
numbers[i] = {
count: 0
}
}
I understand this wont give me the right count, but I don't care about that part of the problem. I would like to solve that on my own. I just need to be sure that this is the correct way to add the object parameters.
I would build these functions on my own. Something like this You can copy and paste this in the console of your browser.
// my numbers list
const numbers = [1, 2, 3, 4, 4, 4, 5, 5, 6];
// reduced to unique entries
const uniques = [...new Set(numbers)];
// function to count occurrences in my list of number
const count = (n) => numbers.filter((num) => num === n).length;
// you can test here
console.log(`counting ${uniques[4]}s`, count(uniques[4]));
// get these as object
console.log(uniques.map((unique) => ({[unique]: count(unique)})))
Simplest way to achieve this by using Array.forEach().
let numbers = [1,2,3,4,4,4,5,5,6];
const obj = {};
numbers.forEach((item) => {
obj[item] = (obj[item] || 0) + 1;
});
console.log(obj);const numbers = [1,2,3,4,4,4,5,5,6];
const counts = {};
numbers.forEach((x) => counts[x] = (counts[x] || 0) + 1);
console.log(counts)