I have the following js and receiving error at the foreach loop:

function bitCount(n) {
var strBitCount = (n >>> 0).toString(2);
var answer = 0;
var c = '';

foreach(c in strBitCount)
{
    if(Number(c) == 1)
    {
        answer++;
    }
}
  return answer;
}

I have the following js and receiving error at the foreach loop:

function bitCount(n) {
var strBitCount = (n >>> 0).toString(2);
var answer = 0;
var c = '';

foreach(c in strBitCount)
{
    if(Number(c) == 1)
    {
        answer++;
    }
}
  return answer;
}

• javascript
• loops
• foreach

• 2 forEach is an array method: arr.forEach(function (el) {...} – Andy Commented Mar 27, 2016 at 19:40

3 Answers 3

JavaScript has no foreach block as other languages.

What you can do is using Array.prototype.forEach:

Array.from("hello").forEach(function(character) {
  console.log(character);
});

Well, and in ES2015 and above, you can use for..of

for (let character of "hello") {
  console.log(character);
}

You can use an ordinary for loop and index into the string with []:

for (var i = 0; i < strBitCount.length; ++i)
  if (Number(strBitCount[i]) === 1)
    answer++;

Note that you could also just add the digit to answer:

for (var i = 0; i < strBitCount.length; ++i)
  answer += Number(strBitCount[i]); // or +strBitCount[i]

You can filter on those characters in the string that match your test and return the length of that array.

function bitCount(n) {
  var strBitCount = (n >>> 0).toString(2);
  var equalsOne = function (char) { return +char === 1; }
  return [].filter.call(strBitCount, equalsOne).length;
}

DEMO