Javascript Data Type How to - Find the number of occurrences for a given value in an array

Question

We would like to know how to find the number of occurrences for a given value in an array.

Answer


<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
var dataset = [2,2,4,2,6,4,7,8];
function findOccurrences(arr, val) {<!--   w ww .  j a v a 2  s .  c om-->
    var i, j,
        count = 0;
    for (i = 0, j = arr.length; i < j; i++) {
        (arr[i] === val) && count++;
    }
    return count;
}
document.writeln(findOccurrences(dataset, 2));

</script>
</head>
<body>
</body>
</html>

The code above is rendered as follows: