Add javascript Solution for 1 (#83)

* add two sum js

* add two sum js

Co-authored-by: nick.huang <[email protected]>

Author: yaodehaung

README.md

@@ -979,7 +979,7 @@ _If you like this project, please leave me a star._ ★
 |4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_4.java) | |Hard | Divide and Conquer
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_3.java) |  |Medium | HashMap, Sliding Window
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_2.java) | |Medium | LinkedList
-|1|[Two Sum](https://leetcode.com/problems/two-sum/)|[Java](../master/src/main/java/com/fishercoder/solutions/_1.java), [C++](../master/cpp/_1.cpp)|[:tv:](https://www.youtube.com/watch?v=kPXOr6pW8KM&t=)|Easy| HashMap 
+|1|[Two Sum](https://leetcode.com/problems/two-sum/)|[Java](../master/src/main/java/com/fishercoder/solutions/_1.java), [C++](../master/cpp/_1.cpp), [javascript](../master/javascript/_1.js)|[:tv:](https://www.youtube.com/watch?v=kPXOr6pW8KM&t=)|Easy| HashMap 
 
 ## Database
 

javascript/1.js

@@ -0,0 +1,16 @@
+// Two sum
+
+var twoSum = function(nums, target) {
+    var sum = {}
+    for( var i = 0 ; i < nums.length ; i++){
+
+          if(!sum.hasOwnProperty(target - nums[i])){
+             sum[nums[i]] = i;
+
+           }else{
+             return [i , sum[target-nums[i]] ]
+           }
+    }
+};
+
+console.log(twoSum([2,7,11,15],9))