Ajax example with Promisse.

promisse_example.js

function asyncFunc() {
    return new Promise(
        function (resolve, reject) {
            $.get('https://httpbin.org/geta', function(res){
            	resolve(res);
            }).fail(function(res){
            	reject(res.responseText);
            });
        });
}

asyncFunc()
.then(value => { console.log('success:', value) })
.catch(error => { console.log('error:', error) });