Count the number of times a same value appears in a javascript array

Question

I would like to know if there is a native javascript code that does the same thing as this:

function f(array,value){
    var n = 0;
    for(i = 0; i < arr         


        

Answer 1

You could use reduce to get there:

Working example

var a = [1,2,3,1,2,3,4];

var map = a.reduce(function(obj, b) {
  obj[b] = ++obj[b] || 1;
  return obj;
}, {});