Play with promises: call several endpoints and aggregate the result

Promises - fetch => sum ES5.js

var data = [{
    isActive: "1",
    logins: 2000,
    clicks: 1000
}, {
    isActive: "1",
    logins: 3000,
    clicks: 1000
}, {
    isActive: "1",
    logins: 1000,
    clicks: 1000
}];

var result = 0;
var timeouts = [0, 2000, 4000];

var callApi = function(index, timeout) {
    return new Promise(
        function(resolve, reject) {
            window.setTimeout(function() {
                resolve({
                    data: data[index]
                });
            }, timeout);
        }
    );
};

timeouts.forEach(function(timeout, index) {
    callApi(index, timeout)
    .then(function(res) {
        result += res.data.logins;
        console.log(index + " - result: " + result);
    });
});

Promises - fetch => sum ES6.js

const data = [{
    isActive: "1",
    logins: 1000,
    clicks: 1000
}, {
    isActive: "1",
    logins: 2000,
    clicks: 1000
}, {
    isActive: "1",
    logins: 3000,
    clicks: 1000
}];

const callApi = (index, timeout) => {
    return new Promise((resolve, reject) => {
        setTimeout(() => resolve({
            data: data[index]
        }), timeout);
    })
};

let result = 0;
[0, 3000, 0].forEach((timeout, index) => {
    callApi(index, timeout)
        .then(res => {
            result += res.data.logins
            console.log(`Result now in callback ${index + 1}:`, result)
        })
});