JSFiddle - React, Tailwind, and code Playground

JavaScript

function countMatches(str, find) {
    var count = 0;
    var index = str.indexOf(find);
    while (index != -1) {
        count++;
        index = str.indexOf(find, index + 1);
    }
    return count;
}

var msg = "hello world :)";
var tce = [":)", ":(", ":/"];
var countOcurrences = 0;
for (var i = 0; i < tce.length; i++) {
    countOcurrences += countMatches(msg, tce[i]);
}

alert(countOcurrences);