contains duplicate in 3 more languages for some reason

contains-duplicate/sol.js

@@ -0,0 +1,14 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function(nums) {
+    let exists = {};
+    return nums.some(n => {
+        if (exists[n]) {
+            return true;
+        }
+        exists[n] = true;
+        return false;
+    });
+};

contains-duplicate/sol.py

@@ -0,0 +1,8 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        exists = {}
+        for n in nums:
+            if n in exists:
+                return True
+            exists[n] = True
+        return False

contains-duplicate/sol.ts

@@ -0,0 +1,10 @@
+function containsDuplicate(nums: number[]): boolean {
+    let exists = {};
+    return nums.some(n => {
+        if (exists[n]) {
+            return true;
+        }
+        exists[n] = true;
+        return false;
+    });
+};