How to display the number that is most repeated in the array?

Question

I didn't find the simple example with JavaScript;

So I have an array with numbers and I need to show the number which is most repeated in array.

const getNumber = arr => {}

console.log(getNumber([1,2,5,2,8,5,2,10,1]))

Answer 1

const arr = [4,5,4,3,2,1,7,8,4];

const sortArr = (arr) => {
  arr.sort();
    var max=0,result,freq = 0;
    for(var i=0; i < arr.length; i++){
        if(arr[i]===arr[i+1]){
            freq++;
        }
        else {
            freq=0;
        }
        if(freq>max){
            result = arr[i];
            max = freq;
        }
    }
    return result;
}
console.log(sortArr(arr));   //Output 4

Answer 2

Use Array#reduce to get an object with properties for all used numbers and their counts. Than use Object#entries to get out of this an array with the numbers and their counts and again use reduce to finde the number with the max-count. Get the number (first element) and return it.

const getNumber = arr => {
    let counts = arr.reduce((acc, cur) => {
        if (!acc[cur]) {
            acc[cur] = 1;
        } else {
            acc[cur]++;
        }
        return acc;
    },{});
    return Object.entries(counts).reduce(([nr,max], [n, count]) => (count>max) ? [n, count] : [nr, max] )[0];

}

console.log(getNumber([1,2,5,2,8,5,2,10,1]));