day 19 task complete

Author: Sanchitbajaj02

day19/leetcode2721.js

@@ -0,0 +1,33 @@
+// 2721. Execute Asynchronous Functions in Parallel
+// URL -> https://leetcode.com/problems/execute-asynchronous-functions-in-parallel/
+
+/**
+ * @param {Array<Function>} functions
+ * @return {Promise<any>}
+ */
+var promiseAll = function (functions) {
+  return new Promise((resolve, reject) => {
+    let res = [], count = 0;
+
+    for (let i = 0; i < functions.length; i++) {
+      functions[i]()
+        .then(result => {
+          res[i] = result;
+          count++;
+
+          if (count === functions.length) {
+            resolve(res);
+          }
+        })
+        .catch(error => {
+          reject(error);
+        });
+    }
+
+  })
+};
+
+/**
+ * const promise = promiseAll([() => new Promise(res => res(42))])
+ * promise.then(console.log); // [42]
+ */