AJAX callback hell
JavaScript
//test();
promiseValue(300).then( (res) => {
alert(res);
});
alert('execute this first');
async function test()
{
let v = await promiseValue(200);
alert('value: '+ v);
}
function promiseValue(id){
return new Promise((resolve, reject) => {
setTimeout(()=>{
resolve(id+1);
}, 2000);
});
}