first commit

历届学生/王凯/11-16/async.js

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+var async = require("async");
+var request = require('superagent'); 
+
+var urls = [
+  "https://www.npmjs.com/package/async",
+  "https://caolan.github.io/async/",
+  "https://www.baidu.com/",
+  "https://www.tslang.cn/",
+  "http://www.jtthink.com/"
+]
+
+async.mapLimit(urls, 2, async function(value, key) {
+    const response = await fetchs(value)
+    return response
+}, (err, results) => {
+    if (err) throw err
+    // results is now an array of the response bodies
+    console.log(results)
+})
+
+async function fetchs(url){
+  return new Promise(function(resolve,reject){
+    request
+    .get(url)
+    .end((err, res) => {
+      resolve(res.text)
+    });
+  })
+}