function doSomething() {
return new Promise((resolve, reject) => {
console.log("It is done.");
// Succeed half of the time.
if (Math.random() > .5) {
resolve("SUCCESS")
} else {
reject("FAILURE")
}
})
}
const promise = doSomething();
promise.then(successCallback, failureCallback);var promise = new Promise(function(resolve, reject) {
// do some long running async thing…
if (/* everything turned out fine */) {
resolve("Stuff worked!");
}
else {
reject(Error("It broke"));
}
});
//usage
promise.then(
function(result) { /* handle a successful result */ },
function(error) { /* handle an error */ }
);console.log('some piece of code');
examplePromise.then(function(result){
console.log(result);
}).catch(function (error) {
console.error(error);
});
console.log('another piece of code');let promise = new Promise((resolve,reject)=>{
try {
resolve("some data");
} catch (error) {
reject(error);
}
})
promise.then(function (data) {
console.log(data);
},function (error) {
console.error(error);
})let promise = new Promise(function(resolve, reject){
try{
resolve("works"); //if works
} catch(err){
reject(err); //doesn't work
}
}).then(alert, console.log); // if doesn't work, then console.log it, if it does, then alert "works"let examplePromise = new Promise(function (resolve, reject) {
let sum;
setTimeout(function(){
sum = 5 + 6;
if(sum > 10) {
resolve(sum);
}else{
reject('The promise has been rejected');
}
}, 2000);
});