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"const count = true;
let countValue = new Promise(function (resolve, reject) {
if (count) {
resolve("There is a count value.");
} else {
reject("There is no count value");
}
});
console.log(countValue);/*
A promise is a building object of JavaScript, using it we can easily do
asynchronous tasks. Also, the concept that is used to create clean code
basically promises.
*/
//Promise
let firstPromise = new Promise((resolved, reject) => {
let fullName = 'Muhammad Shahnewaz';
setTimeout(() => resolved(fullName), 3000); //we need to use setTimeout()
}).then((name) => {
console.log('I am ' + name); //Muhammad Shahnewaz
});