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| const timeout = ms => new Promise((resolve, reject) => {
setTimeout(() => {
resolve();
}, ms);
});
const ajax1 = () => timeout(2000).then(() => {
console.log('1');
return 1;
});
const ajax2 = () => timeout(1000).then(() => {
console.log('2');
return 2;
});
const ajax3 = () => timeout(2000).then(() => {
console.log('3');
return 3;
});
function mergePromise(arr) {
const ret = [];
return new Promise((resolve, reject) => {
arr.reduce((pre, cur) => {
return pre.then(cur).then(res => {
ret.push(res);
if (ret.length === arr.length) {
resolve(ret)
}
});
}, Promise.resolve());
})
}
mergePromise([ajax1, ajax2, ajax3]).then(data => {
console.log('done');
console.log(data);
});
|