Create Promise.all.js

Author: lijinke666

Promise.all.js

@@ -0,0 +1,26 @@
+const sleep = (duration) =>
+  new Promise((resolve) => setTimeout(() => resolve(duration), duration));
+
+async function all(list) {
+  return new Promise((res, rej) => {
+    let count = 0;
+    const result = [];
+
+    list.forEach((item) => {
+      Promise.resolve(item)
+        .then((data) => {
+          result.push(data);
+          count++;
+
+          if (count === list.length) {
+            res(result);
+          }
+        })
+        .catch(rej);
+    });
+  });
+}
+
+all([sleep(1000), sleep(2000), sleep(3000)]).then((res) => {
+  console.log(res);
+});