Basic Logging
HTML
<div id="log">
</div>
JavaScript
function log(s) {
let logEl = document.getElementById('log');
logEl.innerHTML += s;
logEl.innerHTML += '<br>';
}
function doSomethingRisky() {
return new Promise((resolve, reject)=>{
setTimeout(()=>{throw new Error("Oops!");},1);
});
}
new Promise((resolve, reject)=>{
doSomethingRisky();
}).then(number=>{
log("Number is: " + number);
}).catch(e=>{
log("Error is: " + e);
});