javascript promise resolve when done code example
Example 1: promise resolve reject
function testFunction(value) {
return new Promise(function (resoleve, reject) {
setTimeout(function () {
let n = value;
if (n < 100) {
resoleve("範囲内");
} else {
reject("範囲外");
}
}, 2000);
})
}
testFunction(10)
.then(function (value) {
console.log(value);
return testFunction(50);
})
.then(function (value) {
console.log(value);
return testFunction(150);
})
.catch(function (error) {
console.log(`エラーです。${error}`);
})
Example 2: Promise.resolve
var original = Promise.resolve(33);
original.then( val => console.log('origianl', val);
var cast = Promise.resolve(original);
cast.then(function(value) {
console.log('value: ' + value);
});
console.log('original === cast ? ' + (original === cast));