Simplest way to get count of keys with a particular value

Question

Given a javascript object, what is the simplest way to get the number of keys with a particular value?

For example, I have the following javascript obje

Answer 1

Just filter and get the length.

var result = { 1: "PASS", 2: "PASS", 3: "FAIL", 4: "PASS", 5: "FAIL" };

function getCount(s, o) {
    return Object.keys(result).filter(function (k) { return o[k] === s; }).length;
}

document.write(getCount('PASS', result));

Answer 2

function countKeys(data, expected) {
  return Object.keys(data).map(key => data[key] == expected).reduce((p, c) => p + c, 0);
}

Take the object's keys, compare each one and convert to a boolean, then add the booleans together (coerces them to 0 for false, 1 for true, and sums).

With ES5, breaking this down, you can:

function countKeys(data, expected) {
  var keys = Object.keys(data);
  var checked = keys.map(function (key) {
    return data[key] == expected;
  });
  return checked.reduce(function (prev, cur) {
    return prev + cur;
  }, 0);
}

or with the even-older loops:

function countKeys(data, expected) {
  var keys = Object.keys(data);
  var count = 0;
  for (var i = 0; i < keys.length; ++i) {
    var value = data[key];
    if (value == expected) {
      ++count;
    } else {
      // do nothing or increment some failed counter
    }
  }
  return count;
}

Answer 3

var result = {1: "PASS", 2: "PASS", 3: "FAIL", 4: "PASS", 5: "FAIL"};

undefined

function getCountByValue(obj,value){
  return Object.keys(result).filter(function(key){
  return result[key] === value

}).length

}

//as your wish
getCountByValue(result,'FAIL')
getCountByValue(result,'PASS')

Answer 4

You would use Object.keys and Array.filter:

var result = {1: "PASS", 2: "PASS", 3: "FAIL", 4: "PASS", 5: "FAIL"};
var passCount = Object.keys(result).filter(function(key){
   return ( result[key] === 'PASS' );
}).length;