code added

Author: Bharat2044

12_addTwoPromises.js

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+// Question Link: https://leetcode.com/problems/add-two-promises/description/?envType=study-plan-v2&envId=30-days-of-javascript
+// Solution Link: https://leetcode.com/problems/add-two-promises/solutions/5439365/2-different-easy-javascript-solution/
+
+/*
+2723. Add Two Promises
+
+Given two promises promise1 and promise2, return a new promise. promise1 and promise2 will both resolve with a number. The returned promise should resolve with the sum of the two numbers.
+ 
+Example 1:
+Input: 
+promise1 = new Promise(resolve => setTimeout(() => resolve(2), 20)), 
+promise2 = new Promise(resolve => setTimeout(() => resolve(5), 60))
+Output: 7
+Explanation: The two input promises resolve with the values of 2 and 5 respectively. The returned promise should resolve with a value of 2 + 5 = 7. The time the returned promise resolves is not judged for this problem.
+
+Example 2:
+Input: 
+promise1 = new Promise(resolve => setTimeout(() => resolve(10), 50)), 
+promise2 = new Promise(resolve => setTimeout(() => resolve(-12), 30))
+Output: -2
+Explanation: The two input promises resolve with the values of 10 and -12 respectively. The returned promise should resolve with a value of 10 + -12 = -2.
+ 
+Constraints:
+promise1 and promise2 are promises that resolve with a number
+*/
+
+
+
+/**
+ * @param {Promise} promise1
+ * @param {Promise} promise2
+ * @return {Promise}
+ */
+
+/*
+// 1st Approach 
+var addTwoPromises = async function(promise1, promise2) {
+    const num1 = await promise1;
+    const num2 = await promise2;
+
+    return num1 + num2;
+};
+*/
+
+// 2nd Approach
+var addTwoPromises = async function(promise1, promise2) {
+    const [num1, num2] = await Promise.all([promise1, promise2]);
+
+    return num1 + num2;
+};
+
+/**
+ * addTwoPromises(Promise.resolve(2), Promise.resolve(2))
+ *   .then(console.log); // 4
+ */