How to count duplicate value in an array in javascript

Question

Currently, I got an array like that:

var uniqueCount = Array();

After a few steps, my array looks like that:

uniqueCount =          


        

Answer 1

function count() {
    array_elements = ["a", "b", "c", "d", "e", "a", "b", "c", "f", "g", "h", "h", "h", "e", "a"];

    array_elements.sort();

    var current = null;
    var cnt = 0;
    for (var i = 0; i < array_elements.length; i++) {
        if (array_elements[i] != current) {
            if (cnt > 0) {
                document.write(current + ' comes --> ' + cnt + ' times
');
            }
            current = array_elements[i];
            cnt = 1;
        } else {
            cnt++;
        }
    }
    if (cnt > 0) {
        document.write(current + ' comes --> ' + cnt + ' times');
    }

}

count();

Demo Fiddle

You can use higher-order functions too to do the operation. See this answer