countNumbers.js

/** 
 * Count all the numbers in an array
 * 
 * @param {number[]} arr - An array containing numbers
 * @returns {object} - an object where the key is the number, and the value is the count of that number
 * 
 * ex: countNumbers([1,1,1,2,2,3,4]) 
 * returns { 1:3, 2:2, 3:1, 4:1 }
 * 
 * ex: countNumbers([99, 99, 11, 12, 13, 58])
 * returns { 99: 2, 11: 1, 12: 1, 13: 1, 58: 1 }
 */


 //count number returns an object, so create an empty object
 //need to count the occurence of those numbers in the array
 //needs to create a key of each number
 //needs to add values that are the count of number

const countNumbers = (arr) => {
let count = {}
let i = 0
let counter = arr.forEach((key) => {
    return count[key] = (count[key] || 0) + 1
})

return count
 
}

console.log(countNumbers([99, 99, 11, 12, 13, 58]))
module.exports = countNumbers