以setTimeout模拟网络请求的过程
1.
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| new Promise((resolve, reject) => {
setTimeout(() => {
resolve("aaa");
}, 1000);
})
.then((data) => {
console.log(data);
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve(data + "bbb");
}, 1000);
});
})
.then((data) => {
console.log(data);
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve(data + "ccc");
}, 1000);
});
})
.then((data) => {
console.log(data);
});
|
2.new Promise(resolve => resolve(结果))简写为Promise.resolve()
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| new Promise((resolve, reject) => {
setTimeout(() => {
resolve("aaa");
}, 1000);
})
.then((data) => {
console.log(data);
return Promise.resolve(data + "bbb");
})
.then((data) => {
console.log(data);
return Promise.resolve(data + "ccc");
})
.then((data) => {
console.log(data);
});
|
3.省略Promise.resolve
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| new Promise((resolve, reject) => {
setTimeout(() => {
resolve("aaa");
}, 1000);
})
.then((data) => {
console.log(data);
return data + "bbb";
})
.then((data) => {
console.log(data);
return data + "ccc";
})
.then((data) => {
console.log(data);
});
|
