contains-duplicate solution

Author: sap

contains-duplicate/seona926.js

@@ -0,0 +1,16 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+let containsDuplicate = function (nums) {
+  let counts = {};
+
+  return nums.some((num) => {
+    if (counts[num] === undefined) {
+      counts[num] = 1;
+      return false;
+    } else {
+      return true;
+    }
+  });
+};