counting how many times an item appears in a multidimensional array in javascript

Question

Given a multidimensional array like this:

 var arr = [
\"apple\",
[\"banana\", \"strawberry\",\"dsffsd\", \"apple\"],
\"banana\",
[\"sdfdsf\",\"apple\",[\"apple\         


        

Answer 1

You could take a recursive approach for arrays or check the value and add the result of the boolean value.

function count(array, value) {
    return array.reduce((s, a) => s + (Array.isArray(a) ? count(a, value) : a === value), 0);
}

var array = ["apple", ["banana", "strawberry", "dsffsd", "apple"], "banana", ["sdfdsf", "apple", ["apple", ["nonapple", "apple", ["apple"]]]], "apple"];

console.log(count(array, 'apple'));

Version with a for loop.

function count(array, value) {
    var i,
        sum = 0;

    for (i = 0; i < array.length; i++) {
        if (Array.isArray(array[i])) {
            sum += count(array[i], value);
            continue;
        }
        sum += array[i] === value;
    }
    return sum;
}

var array = ["apple", ["banana", "strawberry", "dsffsd", "apple"], "banana", ["sdfdsf", "apple", ["apple", ["nonapple", "apple", ["apple"]]]], "apple"];

console.log(count(array, 'apple'));